Contacts of the helix formed by residues 491 - 516 (chain B) in PDB entry 3IAD


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 PRO 491 (chain B).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    268B  TRP*     4.7     6.3    -      -       +      +
    269B  GLY*     3.8    30.1    -      -       -      +
    489B  THR      4.6     1.3    -      -       -      +
    490B  LYS*     1.3    87.4    -      -       +      +
    492B  LEU*     1.3    56.3    +      -       -      +
    493B  GLN*     3.1    18.8    -      -       +      +
    494B  LEU*     2.6    34.5    +      -       +      +
    495B  TYR      3.3     2.9    +      -       -      -
    564B  THR*     4.1    12.8    -      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 492 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    490B  LYS      3.2     4.4    +      -       -      -
    491B  PRO*     1.3    68.3    -      -       -      +
    493B  GLN*     1.3    64.4    +      -       -      +
    495B  TYR*     3.0    14.1    +      -       +      -
    496B  ARG*     2.9    51.1    +      -       +      +
    564B  THR*     5.0     0.6    -      -       -      +
    568B  ASN*     3.6    31.3    +      -       +      +
    571B  TRP*     3.5    56.5    -      -       +      +
    572B  TYR*     4.6     0.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLN 493 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    269B  GLY      5.5     0.2    -      -       -      +
    271B  HIS*     3.8    18.7    +      -       -      -
    491B  PRO*     3.1    17.5    -      -       +      +
    492B  LEU*     1.3    79.3    -      -       -      +
    494B  LEU*     1.3    62.6    +      -       -      +
    496B  ARG*     3.9     6.5    +      -       -      +
    497B  GLN*     3.3    25.0    +      -       -      +
    802B  EPE      2.7    41.7    +      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 494 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    269B  GLY*     3.8    25.1    -      -       -      +
    270B  LEU      3.4    22.2    -      -       -      +
    271B  HIS*     5.0     0.9    -      -       -      -
    272B  VAL*     3.9    17.7    -      -       +      +
    273B  PHE*     3.7    31.0    -      -       +      -
    333B  ASP*     5.9     0.7    -      -       -      +
    490B  LYS*     4.1    15.7    -      -       +      +
    491B  PRO*     2.6    25.4    +      -       +      +
    493B  GLN*     1.3    80.9    -      -       -      +
    495B  TYR*     1.3    65.4    +      -       -      +
    497B  GLN*     3.3     9.8    +      -       -      +
    498B  TRP*     3.1    33.0    +      -       +      +
    802B  EPE      3.8    11.9    -      -       -      +
----------------------------------------------------------
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Residues in contact with TYR 495 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    487B  ASN*     3.4    31.6    +      -       +      +
    488B  PRO*     3.4    29.6    -      -       +      +
    490B  LYS      3.9    10.3    -      -       -      +
    491B  PRO      3.3     2.0    +      -       -      -
    492B  LEU*     3.0    12.0    +      -       +      +
    494B  LEU*     1.3    77.1    -      -       -      +
    496B  ARG*     1.3    57.9    +      -       -      +
    498B  TRP*     3.1     6.0    +      -       -      +
    499B  THR*     2.9    40.0    +      -       -      -
    535B  GLN*     2.4    40.5    +      -       -      +
    539B  ILE*     3.6    16.4    -      -       +      +
    568B  ASN*     3.8    28.9    -      -       +      -
    572B  TYR*     3.3    30.7    -      +       -      -
    901B  15X      4.3     4.7    -      -       -      -
----------------------------------------------------------
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Residues in contact with ARG 496 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    492B  LEU*     2.9    36.8    +      -       +      +
    493B  GLN*     4.2     6.3    -      -       -      +
    495B  TYR*     1.3    76.1    -      -       -      +
    497B  GLN*     1.3    56.6    +      -       +      +
    499B  THR*     3.3     2.9    +      -       -      -
    500B  ASP*     3.0    35.8    +      -       -      +
    571B  TRP*     3.3    46.4    -      -       -      -
    572B  TYR*     4.0    14.1    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLN 497 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    273B  PHE*     3.6    38.3    -      -       +      +
    493B  GLN*     3.3    18.6    +      -       -      +
    494B  LEU*     3.3     6.7    +      -       -      +
    496B  ARG*     1.3    78.4    -      -       +      +
    498B  TRP*     1.3    58.4    +      -       -      +
    500B  ASP*     3.4     6.9    +      -       -      +
    501B  ARG*     2.9    40.2    +      -       -      +
    802B  EPE      2.9    45.0    +      -       -      -
----------------------------------------------------------
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Residues in contact with TRP 498 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    272B  VAL*     3.9     8.1    -      -       +      -
    273B  PHE*     3.6    36.1    -      +       -      -
    324B  ALA      5.6     0.2    -      -       -      -
    325B  TYR*     3.6    29.4    -      +       -      -
    327B  ASN*     5.4     0.7    -      -       -      -
    329B  ILE*     3.7    12.1    -      -       +      -
    330B  HIS*     3.7    37.9    -      -       +      -
    333B  ASP*     3.5    34.0    +      -       +      -
    487B  ASN*     3.4    39.2    -      -       +      +
    490B  LYS*     5.5     3.8    -      -       +      +
    494B  LEU*     3.1    34.4    +      -       +      +
    495B  TYR*     3.1     7.7    +      -       -      +
    497B  GLN*     1.3    75.9    -      -       -      +
    499B  THR*     1.3    60.8    +      -       -      +
    501B  ARG*     4.3     9.0    -      -       -      -
    502B  ILE*     3.0    31.0    +      -       -      +
    901B  15X      4.2     2.0    -      -       -      -
----------------------------------------------------------
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Residues in contact with THR 499 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    495B  TYR*     2.9    32.8    +      -       -      -
    496B  ARG      3.6     4.3    -      -       -      -
    498B  TRP*     1.3    77.5    -      -       -      +
    500B  ASP*     1.3    59.7    +      -       -      +
    502B  ILE*     3.1     3.3    -      -       -      +
    503B  MET*     3.0    35.4    +      -       +      +
    531B  VAL*     4.0    20.2    -      -       +      -
    535B  GLN*     3.7    28.7    -      -       +      +
    572B  TYR*     3.1    26.5    +      -       -      +
    901B  15X      3.7     8.2    -      -       -      -
----------------------------------------------------------
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Residues in contact with ASP 500 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    496B  ARG*     3.0    22.2    +      -       -      +
    497B  GLN*     3.7     6.7    -      -       -      +
    499B  THR*     1.3    81.2    -      -       -      +
    501B  ARG*     1.3    58.4    +      -       +      +
    503B  MET*     4.0     4.9    -      -       -      +
    504B  GLU*     3.1    27.5    +      -       -      +
    531B  VAL*     5.8     2.8    -      -       -      +
    572B  TYR*     5.5     0.7    +      -       -      -
----------------------------------------------------------
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Residues in contact with ARG 501 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    273B  PHE*     3.2    41.7    -      -       -      -
    324B  ALA*     3.0    51.1    +      -       +      +
    325B  TYR*     4.1     8.5    -      -       +      -
    327B  ASN*     3.6    11.5    +      -       -      +
    329B  ILE*     4.3    12.6    -      -       -      +
    497B  GLN*     2.9    26.3    +      -       -      +
    498B  TRP*     3.8    12.7    -      -       -      +
    499B  THR      3.3     0.4    -      -       -      -
    500B  ASP*     1.3    77.6    -      -       +      +
    502B  ILE*     1.3    64.1    +      -       -      +
    504B  GLU*     3.3     1.8    +      -       -      -
    505B  GLU*     3.1    19.8    +      -       -      +
----------------------------------------------------------
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Residues in contact with ILE 502 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    325B  TYR*     3.5    41.0    -      -       +      -
    326B  HIS*     4.0     3.6    -      -       +      -
    498B  TRP      3.0    16.7    +      -       -      +
    499B  THR*     3.1    13.5    -      -       +      +
    501B  ARG*     1.3    76.1    -      -       -      +
    503B  MET*     1.3    63.7    +      -       +      +
    505B  GLU*     3.5     3.0    +      -       -      +
    506B  PHE*     2.9    69.8    +      -       +      -
    901B  15X      3.5    57.9    -      -       +      +
----------------------------------------------------------
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Residues in contact with MET 503 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    499B  THR*     3.0    24.4    +      -       +      +
    500B  ASP*     4.0     5.8    -      -       -      +
    502B  ILE*     1.3    76.4    -      -       +      +
    504B  GLU*     1.3    59.1    +      -       -      +
    506B  PHE*     3.7     6.4    -      -       +      +
    507B  PHE*     2.9    68.4    +      -       +      -
    523B  MET*     3.4    32.5    -      -       +      +
    529B  ALA*     4.9     2.9    -      -       +      -
    531B  VAL*     4.1    35.7    -      -       +      -
    535B  GLN*     5.3     0.2    -      -       -      -
    901B  15X      3.8    30.5    -      -       -      -
----------------------------------------------------------
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Residues in contact with GLU 504 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    324B  ALA*     3.7    17.7    -      -       +      +
    500B  ASP      3.1    19.2    +      -       -      +
    501B  ARG*     3.3     5.3    +      -       -      +
    503B  MET*     1.3    75.4    -      -       -      +
    505B  GLU*     1.3    63.1    +      -       -      +
    507B  PHE*     3.3     9.7    +      -       +      +
    508B  ARG*     3.0    22.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 505 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    323B  VAL*     2.8    33.8    -      -       +      +
    324B  ALA*     3.7     9.7    +      -       +      +
    325B  TYR*     2.8    21.2    +      -       +      -
    326B  HIS*     2.5    35.4    +      -       -      -
    370B  HIS*     4.0     0.5    -      -       -      -
    372B  GLY*     3.6    32.4    -      -       -      +
    501B  ARG      3.1    14.9    +      -       -      +
    502B  ILE*     3.7     6.8    -      -       -      +
    504B  GLU*     1.3    77.1    -      -       -      +
    506B  PHE*     1.3    65.7    +      -       +      +
    508B  ARG*     3.3     9.2    +      -       +      +
    509B  GLN*     3.3    16.6    +      -       -      +
----------------------------------------------------------
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Residues in contact with PHE 506 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    326B  HIS*     5.3     2.0    -      +       -      -
    502B  ILE*     2.9    42.5    +      -       +      +
    503B  MET*     3.7    16.6    -      -       -      +
    505B  GLU*     1.3    83.2    -      -       +      +
    507B  PHE*     1.3    58.2    +      -       -      +
    509B  GLN*     3.1     8.9    +      -       +      +
    510B  GLY      3.0    22.2    +      -       -      -
    523B  MET*     3.8    24.2    -      -       +      +
    524B  CYS*     3.3    22.9    -      -       -      +
    599B  PHE*     3.4    32.5    -      +       -      -
    901B  15X      3.4    57.4    -      +       -      -
----------------------------------------------------------
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Residues in contact with PHE 507 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    503B  MET*     2.9    54.6    +      -       +      +
    504B  GLU*     3.7     9.4    -      -       +      +
    506B  PHE*     1.3    76.0    -      -       -      +
    508B  ARG*     1.3    56.0    +      -       -      +
    510B  GLY*     3.4     0.9    +      -       -      -
    511B  ASP*     2.9    35.8    +      -       -      +
    523B  MET      3.9     5.4    -      -       -      -
    524B  CYS      3.5    18.0    -      -       -      +
    525B  ASP      3.7     9.0    -      -       -      -
    526B  LYS*     3.6    41.3    -      -       +      -
    529B  ALA*     3.8    16.2    -      -       +      -
    531B  VAL*     4.5     8.5    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 508 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    372B  GLY      5.8     1.3    -      -       -      +
    504B  GLU*     3.0    15.2    +      -       -      +
    505B  GLU*     3.5    12.8    -      -       +      +
    506B  PHE      3.2     0.2    -      -       -      -
    507B  PHE*     1.3    74.8    -      -       -      +
    509B  GLN*     1.3    58.0    +      -       -      +
    511B  ASP*     3.4    10.0    +      -       -      +
    512B  ARG*     3.0    34.3    +      -       +      +
----------------------------------------------------------
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Residues in contact with GLN 509 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    372B  GLY      4.2     3.3    +      -       -      +
    373B  VAL*     3.2    18.8    -      -       +      -
    374B  SER*     3.0    46.4    +      -       -      -
    377B  PHE*     3.9    18.1    -      -       +      +
    505B  GLU      3.3     8.3    +      -       -      +
    506B  PHE*     3.1    13.6    +      -       +      +
    508B  ARG*     1.3    75.9    -      -       -      +
    510B  GLY*     1.3    55.2    +      -       -      +
    512B  ARG*     3.0     8.3    +      -       -      +
    513B  GLU*     2.7    58.9    +      -       -      +
    521B  SER*     3.6    12.5    +      -       -      -
    524B  CYS*     4.6     8.9    -      -       -      -
    901B  15X      5.1     2.2    +      -       -      -
----------------------------------------------------------
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Residues in contact with GLY 510 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    506B  PHE      3.0    10.3    +      -       -      -
    507B  PHE      3.4     0.4    +      -       -      -
    508B  ARG      3.4     0.2    -      -       -      -
    509B  GLN*     1.3    76.9    -      -       -      +
    511B  ASP*     1.3    56.2    +      -       -      +
    513B  GLU*     3.2    16.2    +      -       -      +
    514B  ARG*     2.9    34.1    +      -       -      +
    520B  ILE*     4.0     9.8    -      -       -      +
    524B  CYS*     3.3    24.2    -      -       -      +
----------------------------------------------------------
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Residues in contact with ASP 511 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    507B  PHE*     2.9    25.2    +      -       -      +
    508B  ARG*     3.5     9.4    -      -       -      +
    509B  GLN      3.3     0.2    -      -       -      -
    510B  GLY*     1.3    74.9    -      -       -      +
    512B  ARG*     1.3    62.8    +      -       +      +
    514B  ARG*     2.8    30.5    +      -       -      +
    515B  GLU*     3.3    31.1    +      -       -      +
    526B  LYS*     3.1    32.9    +      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 512 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    371B  PRO*     4.2    14.3    +      -       -      +
    373B  VAL*     3.2    35.6    -      -       -      +
    377B  PHE*     4.2    26.0    -      -       +      -
    508B  ARG*     3.0    20.5    +      -       +      +
    509B  GLN*     3.0     9.1    +      -       -      +
    511B  ASP*     1.3    75.4    -      -       +      +
    513B  GLU*     1.3    64.0    +      -       -      +
    515B  GLU*     3.5    14.7    -      -       -      +
    516B  ARG*     3.4    33.5    +      -       -      +
    282D  ARG*     4.3     5.6    -      -       -      +
    317D  ASP*     2.9    47.5    +      -       -      +
    318D  HIS*     6.1     1.4    -      -       -      -
----------------------------------------------------------
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Residues in contact with GLU 513 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    377B  PHE*     3.8    18.5    -      -       +      +
    509B  GLN*     2.7    36.3    +      -       -      +
    510B  GLY*     3.5    21.4    +      -       -      +
    512B  ARG*     1.3    73.0    -      -       -      +
    514B  ARG*     1.3    61.3    +      -       -      +
    516B  ARG*     3.3     1.7    +      -       -      -
    517B  GLY      3.1     3.5    +      -       -      -
    518B  MET*     2.9    49.2    +      -       +      +
    519B  GLU      3.8    15.5    -      -       -      +
    520B  ILE*     3.5     4.8    -      -       -      -
    521B  SER*     2.6    47.4    +      -       -      -
    524B  CYS*     4.1     0.7    -      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 514 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    510B  GLY      2.9    15.0    +      -       -      +
    511B  ASP*     2.8    37.9    +      -       -      +
    512B  ARG      3.3     0.2    -      -       -      -
    513B  GLU*     1.3    73.6    -      -       -      +
    515B  GLU*     1.3    66.9    +      -       -      +
    517B  GLY*     3.0    14.3    +      -       -      -
    518B  MET      4.7     2.9    -      -       -      -
    520B  ILE*     3.2    24.9    -      -       +      +
    524B  CYS      5.4     0.2    +      -       -      -
    525B  ASP*     2.9    27.3    +      -       -      +
    526B  LYS*     3.9    21.8    -      -       -      +
    527B  HIS*     3.4    21.5    +      -       -      -
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Residues in contact with GLU 515 (chain B). Click here for Legend to table.
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                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
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    511B  ASP*     3.3    17.1    +      -       -      +
    512B  ARG*     3.5    20.9    -      -       -      +
    514B  ARG*     1.3    79.7    -      -       -      +
    516B  ARG*     1.3    61.8    +      -       -      +
    517B  GLY      3.4     0.5    +      -       -      -
    280D  GLY      5.5     0.7    -      -       -      +
    282D  ARG*     2.9    51.3    +      -       -      +
    309D  ILE*     5.7     1.2    -      -       -      +
    313D  MET*     3.8    32.4    -      -       +      +
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Residues in contact with ARG 516 (chain B). Click here for Legend to table.
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                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
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    377B  PHE*     3.9    20.6    -      -       -      -
    381B  THR*     3.9    17.9    -      -       -      +
    512B  ARG*     3.4    25.8    +      -       -      +
    513B  GLU      3.3     5.7    +      -       -      +
    514B  ARG      3.2     1.0    -      -       -      -
    515B  GLU*     1.3    80.4    +      -       -      +
    517B  GLY*     1.3    60.4    +      -       -      +
    518B  MET*     3.5    28.7    +      -       +      +
    310D  THR*     4.1    25.3    +      -       +      +
    313D  MET*     4.5    16.8    -      -       -      +
    314D  THR*     3.3    37.3    +      -       -      +
    317D  ASP*     3.5    24.2    +      -       -      +
    409D  GLU*     5.1     2.6    +      -       -      -
    410D  GLU      5.5     0.8    +      -       -      -
    412D  CYS*     5.5     0.6    -      -       -      -
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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
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  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) +   -    +    +   +   +    +    -
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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