Contacts of the helix formed by residues 239 - 260 (chain O) in PDB entry 2I2X


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 ALA 239 (chain O).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    179O  ASN*     5.7     0.2    +      -       -      -
    238O  LEU*     1.3    75.4    -      -       -      +
    240O  HIS*     1.3    59.6    +      -       -      +
    241O  THR*     3.8     8.1    -      -       -      +
    242O  ILE*     2.9    30.3    +      -       +      +
    243O  ALA*     3.1     8.8    +      -       -      +
    417O  PHE*     4.6    15.7    -      -       +      -
    418O  GLU*     5.0     6.3    -      -       -      -
    421O  ALA*     3.8    28.7    -      -       +      -
     94P  PHE*     3.5    16.4    -      -       -      +
     96P  PRO*     5.8     0.4    -      -       -      +
----------------------------------------------------------
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Residues in contact with HIS 240 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    230O  GLY*     2.7    29.4    +      -       -      -
    231O  GLY      3.2    16.6    +      -       -      -
    232O  GLY      3.3    18.9    +      -       -      -
    233O  LEU*     4.1     9.8    +      -       +      -
    235O  ASN*     5.3     0.6    +      -       -      +
    238O  LEU      3.4    14.6    -      -       -      -
    239O  ALA*     1.3    72.3    -      -       -      +
    241O  THR*     1.3    55.9    +      -       -      +
    243O  ALA*     3.2     7.1    +      -       -      +
    244O  VAL*     3.0    30.0    +      -       -      +
    298O  VAL*     5.5     3.1    -      -       +      -
    364O  ASP*     2.4    42.3    +      -       -      +
    365O  PRO*     4.1     6.2    -      -       +      +
    366O  GLN*     3.4    14.2    +      -       -      +
    418O  GLU*     3.9    18.0    +      -       -      +
     15P  ARG*     4.3     2.6    +      -       -      -
     94P  PHE*     5.4     2.2    -      +       -      -
----------------------------------------------------------
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Residues in contact with THR 241 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    239O  ALA*     3.8     1.7    -      -       -      +
    240O  HIS*     1.3    77.0    -      -       -      +
    242O  ILE*     1.3    61.3    +      -       -      +
    244O  VAL*     3.3    21.3    -      -       -      +
    245O  ILE*     3.4    17.4    -      -       -      +
    365O  PRO*     4.0    17.9    -      -       +      -
    404O  ILE*     4.6     4.7    -      -       +      -
    414O  LEU*     4.3    11.2    -      -       +      -
    418O  GLU*     2.9    48.1    +      -       +      +
    421O  ALA*     3.7    16.1    -      -       -      +
    422O  LEU*     3.8    19.6    +      -       +      +
----------------------------------------------------------
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Residues in contact with ILE 242 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    176O  VAL*     5.7     2.2    -      -       +      -
    179O  ASN*     3.2    41.7    -      -       +      +
    181O  ILE*     4.0    19.3    -      -       +      -
    184O  LEU*     4.0    23.3    -      -       +      -
    226O  ALA*     6.5     0.2    -      -       +      -
    238O  LEU*     3.9    19.3    -      -       +      -
    239O  ALA*     2.9    17.8    +      -       +      +
    241O  THR*     1.3    80.2    +      -       -      +
    243O  ALA*     1.3    64.9    +      -       -      +
    244O  VAL      3.2     0.2    -      -       -      -
    245O  ILE*     3.1     6.8    +      -       +      +
    246O  ALA*     3.0    20.5    +      -       +      +
    421O  ALA*     3.9    32.8    -      -       +      +
    425O  ALA*     5.0     2.0    -      -       +      -
----------------------------------------------------------
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Residues in contact with ALA 243 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    223O  ALA      5.3     1.2    -      -       -      +
    226O  ALA*     4.3    25.9    -      -       -      +
    227O  MET*     4.5     1.7    +      -       +      -
    230O  GLY*     5.4     1.1    -      -       -      -
    238O  LEU*     4.3    10.4    -      -       +      +
    239O  ALA      3.1     7.1    +      -       -      +
    240O  HIS*     3.2    17.9    +      -       +      +
    242O  ILE*     1.3    76.0    -      -       -      +
    244O  VAL*     1.3    61.9    +      -       -      +
    246O  ALA*     3.1    15.2    +      -       -      +
    247O  ARG*     3.2    10.7    +      -       -      +
    366O  GLN*     3.5    26.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with VAL 244 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    240O  HIS      3.0    15.8    +      -       -      +
    241O  THR*     3.3    21.1    -      -       -      +
    243O  ALA*     1.3    75.8    -      -       -      +
    245O  ILE*     1.3    62.2    +      -       +      +
    247O  ARG*     3.2     6.7    +      -       +      +
    248O  ALA      3.0    22.2    +      -       -      -
    365O  PRO*     3.3    25.4    -      -       +      +
    366O  GLN*     3.7    19.9    -      -       -      +
    369O  MET*     3.1    40.1    -      -       +      +
    400O  CYS*     3.8    13.0    -      -       -      -
    404O  ILE*     4.2    14.8    -      -       +      -
    422O  LEU*     5.6     0.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with ILE 245 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    181O  ILE*     4.4    15.9    -      -       +      -
    184O  LEU*     5.5     3.1    -      -       +      -
    241O  THR      3.4    18.4    -      -       -      +
    242O  ILE*     3.1    10.8    +      -       +      +
    244O  VAL*     1.3    74.8    -      -       +      +
    246O  ALA*     1.3    66.2    +      -       -      +
    247O  ARG      3.0     1.8    -      -       -      -
    248O  ALA*     3.2     2.5    +      -       -      +
    249O  ILE*     3.0    32.5    +      -       +      +
    397O  ALA*     4.0    23.8    -      -       +      +
    400O  CYS*     4.0    20.0    -      -       -      -
    401O  CYS*     3.7    21.3    -      -       -      -
    422O  LEU*     4.1     6.5    -      -       +      -
    425O  ALA*     3.5    31.9    -      -       +      -
    429O  LEU*     4.5     2.0    -      -       +      -
----------------------------------------------------------
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Residues in contact with ALA 246 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    172O  PHE*     4.8     2.0    -      -       +      -
    176O  VAL*     6.2     0.2    -      -       +      -
    184O  LEU*     4.6    14.0    -      -       +      +
    188O  ILE*     3.8    25.7    -      -       +      +
    223O  ALA*     4.3     9.4    -      -       -      +
    226O  ALA*     4.0    21.1    -      -       +      -
    242O  ILE*     3.0    11.7    +      -       +      +
    243O  ALA      3.1     9.6    +      -       -      +
    245O  ILE*     1.3    76.2    -      -       -      +
    247O  ARG*     1.3    62.1    +      -       -      +
    249O  ILE*     3.4     7.2    +      -       -      +
    250O  SER*     3.1    21.8    +      -       -      -
----------------------------------------------------------
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Residues in contact with ARG 247 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    219O  ASP      5.6     0.4    +      -       -      -
    223O  ALA*     3.6    28.4    +      -       -      +
    224O  ASN*     3.0    29.9    +      -       -      -
    227O  MET*     3.5    29.1    -      -       -      +
    243O  ALA      3.2    10.6    +      -       -      +
    244O  VAL*     3.3    13.7    -      -       +      +
    245O  ILE      3.0     0.4    -      -       -      -
    246O  ALA*     1.3    74.2    -      -       -      +
    248O  ALA*     1.3    66.9    +      -       -      +
    250O  SER*     2.6    24.8    +      -       -      -
    251O  ALA*     3.4     3.3    +      -       -      +
    271O  TYR*     3.4    22.1    -      -       -      +
    272O  GLU*     3.1    43.6    +      -       +      +
    275O  ILE*     5.0     0.8    -      -       +      +
    299O  MET*     5.1     1.6    -      -       -      +
    366O  GLN*     5.2     2.6    +      -       +      +
    369O  MET*     4.0     4.3    -      -       +      -
    370O  LEU*     3.9    28.7    -      -       +      +
----------------------------------------------------------
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Residues in contact with ALA 248 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    244O  VAL      3.0     5.6    +      -       -      +
    245O  ILE      3.2     6.5    +      -       -      +
    247O  ARG*     1.3    75.4    -      -       -      +
    249O  ILE*     1.3    63.5    +      -       -      +
    250O  SER      3.2     0.9    +      -       -      -
    251O  ALA*     3.3     5.4    +      -       -      +
    252O  PRO*     3.3    17.0    -      -       -      +
    275O  ILE*     4.8     3.1    -      -       -      -
    369O  MET*     3.5    25.5    -      -       +      +
    378O  VAL*     4.5     8.6    -      -       +      +
    396O  ALA*     3.6    22.9    -      -       -      +
    397O  ALA*     4.4     1.6    -      -       -      +
    400O  CYS*     3.5    23.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with ILE 249 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    181O  ILE*     5.0     2.0    -      -       +      +
    184O  LEU*     4.1    11.2    -      -       +      +
    185O  LEU*     3.8    37.0    -      -       +      +
    188O  ILE*     3.6    12.5    -      -       +      +
    189O  GLY*     3.5    32.5    -      -       -      +
    245O  ILE*     3.0    34.2    +      -       +      +
    246O  ALA*     3.7     5.8    -      -       -      +
    248O  ALA*     1.3    74.6    -      -       -      +
    250O  SER*     1.3    63.0    +      -       -      +
    252O  PRO*     3.1    17.2    -      -       -      +
    253O  ARG*     3.8     4.3    +      -       -      +
    393O  ALA*     4.3    11.4    -      -       +      +
    397O  ALA*     3.8    22.2    -      -       +      -
    429O  LEU*     5.3     1.8    -      -       +      -
----------------------------------------------------------
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Residues in contact with SER 250 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    188O  ILE*     3.6    10.1    -      -       -      +
    219O  ASP*     3.3    35.4    -      -       -      -
    223O  ALA*     3.9     4.0    -      -       -      +
    246O  ALA      3.1    10.3    +      -       -      -
    247O  ARG*     2.6    23.6    +      -       -      -
    249O  ILE*     1.3    76.6    -      -       -      +
    251O  ALA*     1.3    52.7    +      -       -      +
    253O  ARG*     3.0     4.6    +      -       -      +
    254O  SER*     2.7    36.2    +      -       -      -
    272O  GLU*     3.3    21.4    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 251 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    247O  ARG      3.4     0.2    +      -       -      -
    248O  ALA      3.3     7.9    +      -       -      +
    249O  ILE      3.3     0.2    -      -       -      -
    250O  SER*     1.3    79.6    +      -       -      +
    252O  PRO*     1.4    65.7    -      -       +      +
    254O  SER      3.3     0.7    +      -       -      -
    255O  LEU*     2.8    30.1    +      -       -      +
    272O  GLU*     4.1    15.9    -      -       +      +
    275O  ILE*     3.6    46.7    -      -       +      -
    276O  VAL*     3.8     6.5    -      -       +      +
    279O  ILE*     5.9     0.7    -      -       -      -
    382O  ILE*     4.1     3.1    -      -       +      -
----------------------------------------------------------
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Residues in contact with PRO 252 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    189O  GLY*     5.8     0.7    -      -       -      -
    193O  SER*     4.0     4.0    +      -       -      +
    248O  ALA      3.3    11.2    -      -       -      +
    249O  ILE      3.1    22.9    -      -       -      +
    251O  ALA*     1.4    84.9    -      -       +      +
    253O  ARG*     1.3    60.5    +      -       -      +
    255O  LEU*     3.4    12.7    -      -       +      +
    256O  VAL*     3.4     4.2    -      -       -      +
    382O  ILE*     3.7    21.3    -      -       +      -
    389O  ILE      5.2     0.9    -      -       -      +
    392O  ARG*     3.0    49.2    +      -       +      +
    393O  ALA*     3.7    28.0    -      -       +      +
    396O  ALA*     4.3     0.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 253 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    165O  SER*     3.1    40.2    +      -       -      -
    167O  GLY*     5.2     5.1    +      -       -      +
    188O  ILE*     3.5    32.3    -      -       +      +
    189O  GLY*     4.9     0.4    -      -       -      -
    192O  GLY*     3.9     8.1    -      -       -      -
    193O  SER*     3.7    21.7    +      -       -      +
    196O  MET*     3.6    23.3    -      -       +      +
    217O  ASP*     3.4    14.5    +      -       -      -
    218O  THR      3.1    31.0    +      -       -      +
    219O  ASP*     2.9    28.9    +      -       -      +
    222O  GLN*     4.4     2.8    +      -       -      +
    249O  ILE      3.8     1.5    +      -       -      +
    250O  SER      3.0    10.8    +      -       -      +
    252O  PRO*     1.3    82.3    -      -       -      +
    254O  SER*     1.3    74.2    +      -       -      +
    256O  VAL*     3.1    20.3    +      -       -      +
----------------------------------------------------------
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Residues in contact with SER 254 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    196O  MET*     4.0     2.0    -      -       -      +
    217O  ASP*     5.4     3.1    -      -       -      +
    218O  THR*     4.0     5.0    -      -       -      -
    219O  ASP*     3.5     1.4    +      -       -      +
    250O  SER      2.7    17.9    +      -       -      -
    251O  ALA      4.0     1.1    -      -       -      -
    253O  ARG*     1.3    94.3    +      -       -      +
    255O  LEU*     1.3    65.8    +      -       -      +
    256O  VAL      3.1     1.2    +      -       -      -
    257O  ALA*     3.2    14.6    +      -       -      +
    258O  TYR*     3.4    18.6    -      -       -      -
    272O  GLU*     2.8    35.5    +      -       -      -
    273O  ASN*     5.2     4.3    -      -       -      -
    276O  VAL*     4.4     7.0    -      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 255 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      6O  TYR*     3.9    11.0    -      -       +      +
    251O  ALA      2.8    19.2    +      -       -      +
    252O  PRO*     3.4     7.9    -      -       +      +
    254O  SER*     1.3    76.9    -      -       -      +
    256O  VAL*     1.3    62.7    +      -       -      +
    258O  TYR*     3.0    17.7    +      -       -      -
    259O  GLU*     3.2    33.6    +      -       -      +
    276O  VAL*     4.1     9.3    -      -       +      +
    279O  ILE*     3.8    35.9    -      -       +      -
    280O  THR*     3.6    30.7    -      -       +      -
    382O  ILE*     4.2    10.8    -      -       +      -
    383O  VAL*     5.6     0.4    -      -       +      -
    392O  ARG*     3.6    15.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with VAL 256 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      3O  ALA      5.4     0.4    -      -       -      +
      5O  ARG*     3.9    14.8    -      -       -      +
    193O  SER*     3.7    22.2    -      -       -      +
    196O  MET*     3.6     7.2    -      -       +      -
    197O  GLU*     3.3    43.5    -      -       +      +
    252O  PRO      3.4    17.3    -      -       -      +
    253O  ARG      3.4     9.9    -      -       -      +
    254O  SER      3.1     1.4    +      -       -      -
    255O  LEU*     1.3    73.9    -      -       -      +
    257O  ALA*     1.3    65.6    -      -       -      +
    259O  GLU*     3.2    10.6    +      -       +      +
    260O  ALA*     2.8    23.3    +      -       +      +
    389O  ILE*     5.2     0.2    -      -       +      -
    392O  ARG*     3.5    12.8    -      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 257 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    196O  MET*     3.6    17.9    -      -       +      +
    200O  TRP*     3.7    32.9    -      -       +      +
    217O  ASP      4.3     8.1    -      -       -      +
    254O  SER      3.2    13.9    +      -       -      +
    255O  LEU      3.2     0.4    -      -       -      -
    256O  VAL*     1.3    79.2    -      -       -      +
    258O  TYR*     1.3    66.6    +      -       +      +
    260O  ALA*     3.2     4.0    +      -       -      +
    261O  GLY      3.2     8.1    +      -       -      -
    262O  ALA*     3.0    27.6    +      -       +      +
----------------------------------------------------------
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Residues in contact with TYR 258 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      6O  TYR*     4.5     8.4    +      -       -      +
    215O  ALA      3.2    21.1    -      -       -      -
    216O  GLY*     3.7    11.4    -      -       -      -
    217O  ASP      4.2     6.1    +      -       -      -
    254O  SER*     3.4    24.7    -      -       -      -
    255O  LEU      3.0     8.3    +      -       -      +
    257O  ALA*     1.3    77.0    -      -       +      +
    259O  GLU*     1.3    62.8    -      -       -      +
    260O  ALA      3.1     1.6    -      -       -      -
    261O  GLY*     3.2    10.7    +      -       -      -
    262O  ALA*     3.6    24.6    -      -       +      +
    264O  GLY*     3.6    11.2    -      -       -      -
    266O  GLY*     3.1    27.2    -      -       -      -
    273O  ASN*     4.6     3.4    +      -       -      -
    276O  VAL*     3.7    27.4    -      -       +      -
    280O  THR*     4.2    10.5    -      -       +      -
    282O  MET*     3.5    33.5    -      -       +      +
    284O  MET*     3.8    13.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 259 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      3O  ALA*     3.7    11.0    +      -       -      +
      4O  LYS*     3.1    44.9    +      -       -      +
      5O  ARG*     3.4    21.4    +      -       -      +
      6O  TYR*     3.2    33.9    +      -       +      -
    255O  LEU*     3.2    16.4    +      -       -      +
    256O  VAL*     3.5    11.5    -      -       -      +
    258O  TYR*     1.3    75.4    -      -       -      +
    260O  ALA*     1.3    58.8    +      -       -      +
    261O  GLY      3.4     0.7    +      -       -      -
    392O  ARG*     2.5    46.6    +      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 260 (chain O). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      3O  ALA*     4.2    14.4    -      -       -      +
    197O  GLU*     4.4     9.9    -      -       -      +
    200O  TRP*     3.5    24.1    -      -       +      +
    201O  THR*     3.8    24.8    -      -       -      +
    204O  SER*     3.1    14.9    +      -       -      -
    256O  VAL*     2.8    17.2    +      -       +      +
    257O  ALA      3.5     2.7    -      -       -      -
    258O  TYR      3.1     0.4    -      -       -      -
    259O  GLU*     1.3    77.7    -      -       -      +
    261O  GLY*     1.3    54.5    +      -       -      +
----------------------------------------------------------
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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