Contacts of the helix formed by residues 18 - 48 (chain A) in PDB entry 1G6U


Residue contacts within the protein are derived with the CSU software (Sobolev V., Sorokine A., Prilusky J., Abola E.E. and Edelman M. (1999) Automated analysis of interatomic contacts in proteins. Bioinformatics, 15, 327-332). A short description of the analytical approach is given at the end of the page.
For CSU analysis of other PDB entry

Note:
Non-standard 3 letter residue codes indicate a heterogroup. To identify and analyse, use LPC software

Legend:
Dist - nearest distance (Å) between atoms of two residues
Surf - contact surface area (Å2) between two residues
HB   - hydrophilic-hydrophilic contact (hydrogen bond)
Arom - aromatic-aromatic contact
Phob - hydrophobic-hydrophobic contact
DC   - hydrophobic-hydrophilic contact (destabilizing contact)
+/-  - indicates presence/absence of a specific contacts
*    - indicates residues forming contacts  by their side chain
       (including CA atoms)
Residues in contact with SER 18 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     16A  GLY      3.5     1.2    +      -       -      -
     17A  PHE*     1.4    92.9    -      -       -      +
     19A  PRO*     1.4    64.8    -      -       -      +
     20A  GLU      3.6     1.6    -      -       -      -
     21A  GLU*     3.3    26.1    +      -       -      +
     22A  LEU*     2.9    24.1    +      -       -      +
     46B  LEU*     4.6     6.0    -      -       -      +
----------------------------------------------------------
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Residues in contact with PRO 19 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     16A  GLY*     3.6    22.0    -      -       -      +
     17A  PHE      2.9     6.5    -      -       -      +
     18A  SER*     1.4    86.2    -      -       -      +
     20A  GLU*     1.3    62.8    +      -       +      +
     22A  LEU*     3.8     2.7    -      -       +      +
     23A  ALA*     2.9    29.2    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 20 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     18A  SER      3.6     0.4    -      -       -      -
     19A  PRO*     1.3    74.5    -      -       +      +
     21A  GLU*     1.3    67.9    +      -       +      +
     23A  ALA*     3.3    10.8    +      -       -      +
     24A  ALA*     3.1    22.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 21 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     18A  SER*     3.3    23.2    +      -       -      +
     20A  GLU*     1.3    79.6    -      -       +      +
     22A  LEU*     1.3    62.3    +      -       -      +
     24A  ALA*     3.4     9.8    +      -       -      +
     25A  LEU*     3.3    22.9    +      -       -      +
     46B  LEU*     3.7    31.9    -      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 22 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      9A  LEU*     3.6    34.5    -      -       +      +
     12A  LEU*     3.6    15.9    -      -       +      -
     13A  LYS*     3.5    39.9    -      -       +      +
     17A  PHE*     3.6    34.8    -      -       +      +
     18A  SER      2.9    17.3    +      -       -      +
     19A  PRO*     3.8     3.4    -      -       +      +
     21A  GLU*     1.3    76.4    -      -       -      +
     23A  ALA*     1.3    59.7    +      -       -      +
     25A  LEU*     3.0     7.1    +      -       +      +
     26A  GLU*     2.8    28.4    +      -       +      +
     43B  LEU*     4.2     6.7    -      -       +      -
     46B  LEU*     4.2     3.5    -      -       +      +
----------------------------------------------------------
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Residues in contact with ALA 23 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     13A  LYS*     6.1     2.5    -      -       -      +
     19A  PRO      2.9    18.6    +      -       -      +
     20A  GLU*     3.3    15.9    +      -       -      +
     22A  LEU*     1.3    73.0    -      -       -      +
     24A  ALA*     1.3    66.4    +      -       -      +
     26A  GLU*     3.3    17.5    +      -       -      +
     27A  SER*     3.0    27.8    +      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 24 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     20A  GLU      3.1    12.0    +      -       -      +
     21A  GLU*     3.5    15.7    -      -       -      +
     22A  LEU      3.2     0.2    -      -       -      -
     23A  ALA*     1.3    77.4    -      -       -      +
     25A  LEU*     1.4    64.9    +      -       +      +
     27A  SER*     3.3     5.6    +      -       -      -
     28A  GLU*     3.0    30.1    +      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 25 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      9A  LEU*     3.8    18.7    -      -       +      +
     21A  GLU      3.3    11.0    +      -       -      +
     22A  LEU*     3.0     9.7    +      -       +      +
     24A  ALA*     1.4    80.0    -      -       +      +
     26A  GLU*     1.3    63.1    +      -       -      +
     28A  GLU*     3.2     6.4    +      -       +      +
     29A  LEU*     2.9    24.8    +      -       -      +
     39B  LEU*     4.0    24.8    -      -       +      +
     42B  LYS*     3.9    26.7    -      -       +      -
     43B  LEU*     3.8    34.3    -      -       +      +
     46B  LEU*     3.8    25.8    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 26 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      9A  LEU*     3.9    18.7    -      -       +      +
     10A  GLN*     5.9     5.0    -      -       +      +
     13A  LYS*     2.9    43.1    +      -       -      +
     22A  LEU*     2.8    16.8    +      -       +      +
     23A  ALA*     3.4    18.3    -      -       -      +
     25A  LEU*     1.3    72.3    -      -       -      +
     27A  SER*     1.3    59.4    +      -       -      +
     29A  LEU*     3.3     5.8    +      -       +      +
     30A  GLN*     2.9    53.2    +      -       +      +
----------------------------------------------------------
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Residues in contact with SER 27 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     23A  ALA      3.0    16.6    +      -       -      -
     24A  ALA*     3.8     5.4    -      -       -      -
     25A  LEU      3.3     0.2    -      -       -      -
     26A  GLU*     1.3    75.2    +      -       -      +
     28A  GLU*     1.3    55.7    +      -       -      +
     30A  GLN*     3.1    16.2    +      -       -      +
     31A  ALA*     2.7    34.2    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 28 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     24A  ALA*     3.0    24.1    +      -       +      +
     25A  LEU*     3.7     5.6    -      -       +      +
     27A  SER*     1.3    76.1    -      -       -      +
     29A  LEU*     1.3    57.5    +      -       -      +
     31A  ALA*     3.1    11.9    +      -       -      +
     32A  LEU*     2.9    27.2    +      -       -      +
     35B  LYS*     3.3    32.3    +      -       -      -
     39B  LEU*     3.6    24.2    -      -       +      +
     42B  LYS*     3.3    14.0    +      -       -      +
    201B  SO4      4.1    11.3    +      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 29 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      2A  LEU*     4.0    18.2    -      -       +      -
      5A  LEU*     3.9    23.3    -      -       +      -
      6A  LYS*     3.6    48.5    -      -       +      +
      9A  LEU*     3.9     9.6    -      -       +      -
     25A  LEU      2.9    13.8    +      -       -      +
     26A  GLU*     3.5     9.2    -      -       +      +
     27A  SER      3.2     0.2    -      -       -      -
     28A  GLU*     1.3    76.7    -      -       -      +
     30A  GLN*     1.3    64.6    +      -       +      +
     32A  LEU*     3.1     6.7    +      -       -      +
     33A  GLU*     2.9    47.5    +      -       +      +
     39B  LEU*     3.9    12.2    -      -       +      +
----------------------------------------------------------
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Residues in contact with GLN 30 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      6A  LYS*     6.3     0.4    -      -       -      -
     26A  GLU*     2.9    42.9    +      -       +      +
     27A  SER*     3.1    17.0    +      -       -      +
     29A  LEU*     1.3    78.6    -      -       +      +
     31A  ALA*     1.3    63.9    +      -       -      +
     33A  GLU*     3.1    23.1    +      -       -      +
     34A  LYS*     3.0    33.6    +      -       +      +
----------------------------------------------------------
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Residues in contact with ALA 31 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     27A  SER      2.7    16.7    +      -       -      +
     28A  GLU*     3.1    16.8    +      -       -      +
     30A  GLN*     1.3    72.7    -      -       -      +
     32A  LEU*     1.3    56.3    +      -       -      +
     34A  LYS*     3.3     9.7    +      -       -      +
     35A  LYS*     2.9    30.8    +      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 32 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      2A  LEU*     3.9    29.4    -      -       +      -
     28A  GLU      2.9    12.0    +      -       -      +
     29A  LEU*     3.1     8.5    +      -       -      +
     31A  ALA*     1.3    76.9    -      -       -      +
     33A  GLU*     1.3    57.6    +      -       -      +
     35A  LYS*     3.2     8.3    +      -       -      +
     36A  LEU*     2.8    25.5    +      -       +      +
      2B  LEU*     4.3     9.6    -      -       +      -
     32B  LEU*     3.7    33.8    -      -       +      +
     35B  LYS*     3.8    15.7    -      -       +      -
     36B  LEU*     3.7    38.4    -      -       +      +
     39B  LEU*     4.2    10.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 33 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      2A  LEU*     4.5    17.8    -      -       +      +
      6A  LYS*     2.7    40.9    +      -       -      +
     29A  LEU*     2.9    30.4    +      -       +      +
     30A  GLN*     3.1    29.9    +      -       -      +
     32A  LEU*     1.3    76.8    -      -       -      +
     34A  LYS*     1.3    60.9    +      -       +      +
     36A  LEU*     3.3     9.0    +      -       -      +
     37A  ALA*     3.0    26.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with LYS 34 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     30A  GLN*     3.0    22.0    +      -       +      +
     31A  ALA*     3.5    10.8    -      -       -      +
     33A  GLU*     1.3    77.5    -      -       +      +
     35A  LYS*     1.3    59.0    +      -       +      +
     37A  ALA*     3.2     9.6    +      -       +      +
     38A  ALA*     2.9    28.6    +      -       -      +
----------------------------------------------------------
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Residues in contact with LYS 35 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     31A  ALA      2.9    15.3    +      -       -      +
     32A  LEU*     3.2     8.0    +      -       -      +
     34A  LYS*     1.3    73.9    -      -       +      +
     36A  LEU*     1.3    57.2    +      -       -      +
     38A  ALA*     3.0    15.5    +      -       -      +
     39A  LEU*     2.9    50.2    +      -       -      +
     28B  GLU*     2.9    30.0    +      -       -      +
     32B  LEU*     3.7    25.3    -      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 36 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      2A  LEU*     4.1    13.9    -      -       +      -
     32A  LEU*     2.8    17.2    +      -       +      +
     33A  GLU*     3.5     7.2    -      -       -      +
     34A  LYS      3.2     0.2    -      -       -      -
     35A  LYS*     1.3    77.5    -      -       -      +
     37A  ALA*     1.3    62.4    +      -       -      +
     39A  LEU*     3.2     2.8    +      -       -      +
     40A  LYS*     3.1    28.6    +      -       +      +
      1B  SER*     3.7    34.5    -      -       -      +
      2B  LEU*     3.9    23.1    -      -       +      +
      5B  LEU*     3.5    33.7    -      -       +      -
     29B  LEU*     4.2     3.6    -      -       +      -
     32B  LEU*     3.8    11.8    -      -       +      +
----------------------------------------------------------
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Residues in contact with ALA 37 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     33A  GLU      3.0    14.4    +      -       -      +
     34A  LYS*     3.2    13.9    +      -       +      +
     36A  LEU*     1.3    76.0    -      -       -      +
     38A  ALA*     1.3    58.6    +      -       -      +
     40A  LYS*     3.2    12.4    +      -       -      +
     41A  SER*     2.9    32.1    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 38 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     34A  LYS      2.9    14.4    +      -       -      +
     35A  LYS*     3.0    21.5    +      -       -      +
     37A  ALA*     1.3    78.1    -      -       -      +
     39A  LEU*     1.3    57.8    +      -       -      +
     41A  SER*     3.2     7.4    +      -       -      -
     42A  LYS*     2.9    29.0    +      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 39 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     35A  LYS*     2.9    34.5    +      -       -      +
     36A  LEU      3.2     6.2    +      -       -      +
     38A  ALA*     1.3    78.2    -      -       -      +
     40A  LYS*     1.3    62.4    +      -       -      +
     42A  LYS*     3.2     5.7    +      -       +      +
     43A  LEU*     2.9    23.7    +      -       -      +
      5B  LEU*     3.9    17.0    -      -       +      -
     25B  LEU*     4.0    22.4    -      -       +      +
     28B  GLU*     3.5    28.0    -      -       +      +
     29B  LEU*     3.7    30.7    -      -       +      +
     32B  LEU*     3.7    26.0    -      -       +      -
----------------------------------------------------------
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Residues in contact with LYS 40 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     36A  LEU*     3.1    27.5    +      -       +      +
     37A  ALA*     3.2    11.6    +      -       -      +
     39A  LEU*     1.3    75.7    -      -       -      +
     41A  SER*     1.3    62.3    +      -       -      +
     43A  LEU*     3.3     8.6    +      -       -      +
     44A  GLN*     3.0    22.5    +      -       -      +
      1B  SER      5.5     6.7    -      -       -      +
      4B  ALA*     6.2     2.4    -      -       -      +
      5B  LEU*     4.1    27.5    -      -       +      +
      8B  GLU*     4.4    15.2    +      -       -      -
----------------------------------------------------------
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Residues in contact with SER 41 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     37A  ALA*     2.9    14.2    +      -       -      +
     38A  ALA*     3.6    11.3    -      -       -      -
     39A  LEU      3.2     0.2    -      -       -      -
     40A  LYS*     1.3    76.4    -      -       -      +
     42A  LYS*     1.3    60.8    +      -       -      +
     44A  GLN*     3.1     8.9    +      -       -      +
     45A  ALA*     2.9    28.2    +      -       -      +
----------------------------------------------------------
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Residues in contact with LYS 42 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     38A  ALA      2.9    17.6    +      -       -      +
     39A  LEU*     3.2     8.5    +      -       +      +
     41A  SER*     1.3    74.1    -      -       -      +
     43A  LEU*     1.3    63.2    +      -       -      +
     45A  ALA*     3.2    15.6    +      -       +      +
     46A  LEU*     3.0    34.7    +      -       +      +
     21B  GLU*     4.4    18.9    +      -       -      -
     25B  LEU*     3.7    24.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with LEU 43 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     39A  LEU      2.9    13.6    +      -       -      +
     40A  LYS*     3.5    10.5    -      -       -      +
     42A  LYS*     1.3    78.0    -      -       -      +
     44A  GLN*     1.3    63.3    +      -       -      +
     46A  LEU*     3.1     7.2    +      -       +      +
     47A  LYS*     3.1    29.1    +      -       -      +
      5B  LEU*     3.9    19.3    -      -       +      -
      8B  GLU*     3.7    37.0    -      -       +      +
      9B  LEU*     4.1     5.6    -      -       +      -
     12B  LEU*     3.8    22.0    -      -       +      -
     17B  PHE*     4.2     7.4    -      -       +      -
     22B  LEU*     3.9    23.3    -      -       +      -
     25B  LEU*     4.0    14.5    -      -       +      +
----------------------------------------------------------
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Residues in contact with GLN 44 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     40A  LYS      3.0    13.8    +      -       -      +
     41A  SER*     3.1    10.5    +      -       -      +
     43A  LEU*     1.3    78.7    -      -       -      +
     45A  ALA*     1.3    60.9    +      -       -      +
     47A  LYS*     3.2    30.7    +      -       -      +
     48A  GLY*     3.2    18.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 45 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     41A  SER      2.9    12.7    +      -       -      +
     42A  LYS*     3.2    22.6    +      -       +      +
     44A  GLN*     1.3    74.5    -      -       -      +
     46A  LEU*     1.4    62.3    +      -       -      +
     48A  GLY*     3.1    16.0    +      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 46 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     42A  LYS*     3.0    26.8    +      -       +      +
     43A  LEU*     3.1     8.9    +      -       -      +
     45A  ALA*     1.4    76.9    -      -       -      +
     47A  LYS*     1.3    59.9    +      -       -      +
     48A  GLY      3.5     3.5    +      -       -      -
     17B  PHE*     3.6    20.7    -      -       +      -
     18B  SER*     4.1     8.2    -      -       -      +
     21B  GLU*     3.5    48.7    -      -       +      +
     22B  LEU*     4.2    12.6    -      -       +      -
     25B  LEU*     3.8    29.6    -      -       +      -
----------------------------------------------------------
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Residues in contact with LYS 47 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     43A  LEU*     3.1    29.5    +      -       -      +
     44A  GLN*     3.2    30.4    +      -       -      +
     46A  LEU*     1.3    74.2    -      -       -      +
     48A  GLY*     1.3    65.7    +      -       -      +
      8B  GLU*     3.3    25.2    +      -       -      -
     12B  LEU*     4.2    17.5    -      -       +      -
     17B  PHE*     3.9    21.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLY 48 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     44A  GLN*     3.2     9.5    +      -       -      +
     45A  ALA      3.1    16.4    +      -       -      -
     46A  LEU      4.3     3.8    -      -       -      -
     47A  LYS*     1.3    82.4    -      -       -      +
----------------------------------------------------------
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A short description of the analytical approach
The contact analysis used in this page is based upon the approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129. Contact legitimacy depends on the hydrophobic-hydrophilic properties of the contacting atoms. In order to define it, for each inter-atomic contact, eight atom classes have been introduced:


   I  Hydrophilic      - N and O that can donate and accept hydrogen bonds
                         (e.g., oxygen of hydroxyl group of Ser. or Thr)
  II  Acceptor         - N or O that can only accept a hydrogen bond
 III  Donor            - N that can only donate a hydrogen bond
  IV  Hydrophobic      - Cl, Br, I and all C atoms that are not in
                         aromatic rings and do not have a covalent bond to
                         a N or O atom
   V  Aromatic         - C in aromatic rings irrespective of any other 
                         bonds formed by the atom
  VI  Neutral          - C atoms that have a covalent bond to at least one
                         atom of class I or two or more atoms from class II
                         or III; atoms; S, F, P, and metal atoms in all cases
 VII  Neutral-donor    - C atoms that have a covalent bond with only one
                         atom of class III
VIII  Neutral-acceptor - C atoms that have a covalent bond with only 
                         one atom of class II
For each pair of contacts the state of legitimacy is shown below:

Legend:
+, legitimate
-, illegitimate
------------------------------------------------------------
  Atomic class           I  II  III   IV   V   VI  VII  VIII
------------------------------------------------------------
   I  (Hydrophilic)      +   +    +    -   +   +    +    +
  II  (Acceptor)         +   -    +    -   +   +    +    -
 III  (Donor)            +   +    -    -   +   +    -    +
  IV  (Hydrophobic)      -   -    -    +   +   +    +    +
   V  (Aromatic)         +   +    +    +   +   +    +    +
  VI  (Neutral)          +   +    +    +   +   +    +    +
 VII  (Neutral-donor)    +   +    -    +   +   +    -    +
VIII  (Neutral-acceptor) +   -    +    +   +   +    +    -
------------------------------------------------------------
Warning!
Atom classes for heterogroups are automatically assigned based on the atomic coordinates. However, in three cases (see below) the automatic assignment is currently ambiguous. In these cases, the user is advised to manually analyse the full list of contacts using LPC software.
1. Carbon atoms belonging to a 4-, 5- or 6-member ring are 
   considered "aromatic" (Class V) if the ring is approximately
   planar, and "hydrophobic" (Class IV) or "neutral" (Classes
   VI, VII, VIII) if the ring is non-planar.
2. The oxygen atom of a carbonyl or hydroxy group is considered
   "hydroxy" (Class I) if the CO bond is longer than 1.29 Å, and
   "carbonyl" (Class II) if shorter.
3. All nitrogen atoms are considered "hydrophilic" (Class I).

Please E-mail any questions and/or suggestions concerning this page to Vladimir.Sobolev@weizmann.ac.il