Contacts of the helix formed by residues 643 - 667 (chain A) in PDB entry 5FBQ


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 THR 643 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    638A  HIS      3.9     5.4    +      -       -      +
    639A  GLY*     3.7    17.4    -      -       -      -
    640A  SER*     2.8    34.2    +      -       -      +
    641A  TYR      3.7     0.7    -      -       -      +
    642A  THR*     1.3    77.0    +      -       -      +
    644A  GLU*     1.3    64.7    +      -       -      +
    645A  ALA*     3.8     7.5    +      -       -      +
    646A  PHE*     3.1    26.2    -      -       +      +
    647A  LEU*     3.4    22.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 644 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    642A  THR      4.1     1.3    +      -       -      -
    643A  THR*     1.3    74.9    +      -       -      +
    645A  ALA*     1.3    68.1    +      -       -      +
    646A  PHE      3.0     0.7    +      -       -      -
    647A  LEU*     3.1     3.0    +      -       -      +
    648A  SER*     2.9    27.9    +      -       -      -
     52B  SER*     3.2    23.6    +      -       -      -
     59B  THR*     5.3     5.9    -      -       -      +
     61B  LYS*     2.5    48.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 645 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    638A  HIS*     3.6    32.6    -      -       +      +
    643A  THR*     3.9     4.9    +      -       +      +
    644A  GLU*     1.3    78.0    -      -       -      +
    646A  PHE*     1.3    56.0    +      -       -      +
    648A  SER*     3.9     7.0    +      -       -      -
    649A  ALA*     3.1    27.9    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 646 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    631A  LEU*     4.3    16.2    -      -       +      -
    634A  PHE*     3.8    40.6    -      +       +      -
    635A  LEU*     4.2    11.7    -      -       +      -
    638A  HIS*     4.1     6.2    -      -       +      +
    639A  GLY      3.6    15.0    -      -       -      +
    640A  SER      3.3    20.4    -      -       -      +
    641A  TYR*     3.1    36.8    -      +       +      -
    643A  THR*     3.1    11.4    -      -       +      +
    644A  GLU      3.1     0.8    -      -       -      -
    645A  ALA*     1.3    75.0    -      -       -      +
    647A  LEU*     1.3    60.0    +      -       +      +
    649A  ALA*     2.9     4.7    +      -       -      +
    650A  GLN*     2.6    65.5    +      -       +      +
    717A  VAL*     4.8     3.8    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 647 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    641A  TYR*     3.3    26.2    -      -       +      +
    642A  THR*     5.1     3.8    -      -       -      +
    643A  THR      3.4     9.8    +      -       -      +
    644A  GLU*     3.1     6.3    +      -       -      +
    646A  PHE*     1.3    83.4    -      -       +      +
    648A  SER*     1.3    58.6    +      -       -      +
    650A  GLN*     3.6    22.4    -      -       -      +
    651A  ARG*     2.9    29.1    +      -       -      +
    725A  MET*     5.4     1.2    -      -       -      +
     11B  LEU*     5.0    18.8    -      -       +      -
     61B  LYS*     3.7    34.3    -      -       +      +
     63B  GLN*     6.3     1.1    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 648 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    644A  GLU      2.9    16.5    +      -       -      -
    645A  ALA*     3.9     7.5    +      -       -      -
    647A  LEU*     1.3    77.6    -      -       -      +
    649A  ALA*     1.3    57.7    +      -       -      +
    651A  ARG*     3.3    10.4    +      -       -      +
    652A  ASN*     2.9    44.6    +      -       -      +
    682A  GLU      5.0     0.2    +      -       -      -
     61B  LYS*     5.2     1.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 649 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    634A  PHE*     3.7    22.1    -      -       +      -
    638A  HIS*     3.9    21.5    -      -       +      +
    645A  ALA      3.1    19.8    +      -       -      +
    646A  PHE      2.9     6.1    +      -       -      +
    648A  SER*     1.3    74.2    +      -       -      +
    650A  GLN*     1.3    60.6    +      -       -      +
    652A  ASN*     3.4     2.6    +      -       -      +
    653A  PHE*     2.9    28.2    +      -       -      +
    682A  GLU      3.3    20.0    -      -       -      +
    683A  GLY*     3.8     2.1    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 650 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    634A  PHE*     4.2     4.9    -      -       -      -
    646A  PHE*     2.6    37.6    +      -       +      +
    647A  LEU*     3.6    26.2    -      -       -      +
    649A  ALA*     1.3    72.9    -      -       -      +
    651A  ARG*     1.3    57.8    +      -       -      +
    653A  PHE*     3.1     9.0    +      -       -      +
    654A  VAL*     2.9    40.4    +      -       +      +
    717A  VAL*     2.4    38.3    +      -       +      +
    718A  MET      3.7    13.9    +      -       -      -
    719A  GLY*     3.9     4.6    -      -       -      +
    725A  MET*     3.8    22.8    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 651 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    647A  LEU      2.9    17.7    +      -       -      +
    648A  SER*     3.4     9.9    -      -       -      +
    650A  GLN*     1.3    76.5    -      -       -      +
    652A  ASN*     1.3    63.9    +      -       -      +
    654A  VAL*     3.3     2.3    +      -       -      +
    655A  GLN*     3.1    53.8    +      -       +      +
    725A  MET*     4.1    20.8    -      -       +      +
    728A  TYR*     5.4     2.1    +      -       +      -
     33B  ARG*     6.2     2.2    -      -       -      +
     48B  PHE*     4.5    29.3    +      -       +      -
     49B  ALA*     4.8     9.5    -      -       -      +
     50B  THR*     3.8    25.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 652 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    648A  SER*     2.9    29.3    +      -       -      +
    649A  ALA      3.6     0.9    -      -       -      +
    651A  ARG*     1.3    79.9    -      -       -      +
    653A  PHE*     1.3    62.1    +      -       -      +
    655A  GLN*     4.1    11.0    -      -       -      +
    656A  SER*     3.0    19.9    +      -       -      -
    682A  GLU*     2.8    42.1    +      -       -      +
    683A  GLY      3.9     1.1    -      -       -      -
    684A  HIS*     3.1    42.4    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 653 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    619A  ILE*     6.4     0.4    -      -       +      -
    630A  LEU*     4.1    19.5    -      -       +      -
    634A  PHE*     3.8    18.8    -      +       +      -
    649A  ALA      2.9    12.2    +      -       -      +
    650A  GLN*     3.1    13.9    +      -       -      +
    652A  ASN*     1.3    75.3    -      -       -      +
    654A  VAL*     1.3    59.1    +      -       +      +
    656A  SER*     2.7    18.0    +      -       -      -
    657A  CYS*     2.9    41.5    +      -       -      +
    679A  LEU*     4.5     2.0    -      -       +      -
    683A  GLY      3.2    23.9    +      -       -      +
    685A  ILE*     3.2    27.6    -      -       +      -
    714A  PHE*     4.0    37.7    -      +       -      -
    717A  VAL*     3.8    18.2    -      -       +      -
    718A  MET*     4.3    11.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 654 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    650A  GLN*     2.9    22.8    +      -       +      +
    651A  ARG      3.3     4.5    +      -       -      +
    653A  PHE*     1.3    79.5    -      -       +      +
    655A  GLN*     1.3    62.2    +      -       -      +
    657A  CYS*     3.4     6.9    +      -       -      +
    658A  ALA*     3.2    21.0    +      -       -      +
    718A  MET*     3.9    26.0    -      -       +      -
    725A  MET*     3.7    39.9    -      -       +      +
    728A  TYR*     3.9    18.4    -      -       +      -
    729A  TYR*     3.7    24.8    -      -       +      -
    732A  LEU*     4.4     2.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 655 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    592A  PRO*     3.1    41.8    +      -       -      +
    593A  LEU*     3.8     2.1    -      -       -      -
    594A  TRP*     3.1    30.8    +      -       +      +
    651A  ARG*     3.1    44.6    +      -       -      +
    652A  ASN*     4.2    13.6    -      -       -      +
    654A  VAL*     1.3    76.5    -      -       -      +
    656A  SER*     1.3    61.8    +      -       -      +
    658A  ALA*     3.7     1.1    +      -       -      +
    659A  GLY      3.2    14.7    +      -       -      -
    684A  HIS*     5.3     1.4    +      -       -      -
    728A  TYR*     3.9    12.7    +      -       +      -
    732A  LEU*     3.8    20.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 656 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    594A  TRP*     3.2    28.1    -      -       -      +
    652A  ASN      3.0    15.3    +      -       -      -
    653A  PHE*     2.7    19.8    +      -       -      -
    655A  GLN*     1.3    73.9    -      -       -      +
    657A  CYS*     1.3    64.0    +      -       -      +
    658A  ALA      3.4     0.2    -      -       -      -
    660A  TYR*     3.2    31.5    +      -       -      +
    684A  HIS*     3.5     0.8    -      -       -      -
    685A  ILE*     3.0    43.0    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with CYS 657 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    653A  PHE*     2.9    47.0    +      -       -      +
    654A  VAL      3.6     3.6    -      -       -      +
    655A  GLN      3.3     0.2    -      -       -      -
    656A  SER*     1.3    76.2    +      -       -      +
    658A  ALA*     1.3    59.6    +      -       -      +
    660A  TYR      3.5     0.3    +      -       -      -
    661A  CYS*     3.0    31.0    +      -       -      +
    685A  ILE*     3.7    23.3    -      -       -      -
    708A  PHE*     4.2     8.3    -      -       +      -
    710A  LEU*     5.3     0.9    -      -       -      -
    714A  PHE*     4.0    12.6    -      -       -      -
    718A  MET*     3.8    11.4    -      -       +      -
    729A  TYR*     3.4    20.8    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 658 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    593A  LEU*     3.6    23.6    -      -       +      -
    654A  VAL      3.2    13.5    +      -       -      +
    655A  GLN      4.0     1.1    -      -       -      +
    657A  CYS*     1.3    77.1    -      -       -      +
    659A  GLY*     1.3    65.4    +      -       -      +
    661A  CYS*     3.5     3.0    -      -       -      +
    662A  LEU*     3.2    27.9    +      -       -      +
    729A  TYR*     3.3    22.6    -      -       +      +
    732A  LEU*     3.9     5.8    -      -       +      -
    733A  MET*     3.8    19.1    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 659 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    586A  TRP*     3.7     2.9    -      -       -      -
    593A  LEU*     4.1    20.9    -      -       -      +
    595A  ILE*     3.8    20.4    -      -       -      -
    655A  GLN      3.2    13.9    +      -       -      -
    656A  SER      4.0     0.4    -      -       -      -
    658A  ALA*     1.3    78.4    -      -       -      +
    660A  TYR*     1.3    60.3    +      -       -      +
    662A  LEU*     3.2     7.3    +      -       -      +
    663A  VAL*     3.2    23.4    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 660 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    579A  LEU*     4.9     7.0    -      -       +      -
    594A  TRP*     4.2     2.0    -      +       -      -
    595A  ILE*     3.9    25.1    -      -       +      -
    596A  LYS*     3.0    37.7    +      -       -      +
    656A  SER      3.2    26.0    +      -       -      +
    657A  CYS      4.3     2.0    -      -       -      +
    659A  GLY*     1.3    73.3    -      -       -      +
    661A  CYS*     1.3    61.4    +      -       -      +
    663A  VAL*     3.6    14.1    -      -       +      +
    664A  CYS*     2.8    37.5    +      -       -      -
    685A  ILE*     3.2    30.3    -      -       +      -
    686A  ILE*     3.4    13.3    -      -       +      +
    687A  HIS*     3.6    54.5    +      +       +      +
    690A  PHE*     4.7     9.9    -      +       -      -
    708A  PHE*     5.2     1.3    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with CYS 661 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    657A  CYS      3.0    19.3    +      -       -      +
    658A  ALA      3.5     5.8    -      -       -      +
    660A  TYR*     1.3    77.9    -      -       -      +
    662A  LEU*     1.3    55.8    +      -       -      +
    664A  CYS*     3.2     3.6    +      -       -      +
    665A  TYR*     2.9    27.5    +      -       -      +
    708A  PHE*     3.5    31.1    -      -       +      +
    729A  TYR*     3.6    12.8    -      -       -      +
    733A  MET*     3.4    31.4    -      -       -      -
    792A  MET*     4.3     9.6    -      -       -      -
    796A  SER*     5.8     4.5    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 662 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    586A  TRP*     3.8    22.0    -      -       +      -
    593A  LEU*     3.8    10.5    -      -       +      -
    658A  ALA      3.2    10.4    +      -       -      +
    659A  GLY      3.2     9.3    +      -       -      +
    661A  CYS*     1.3    79.0    -      -       -      +
    663A  VAL*     1.3    58.1    +      -       -      +
    665A  TYR*     3.3     3.5    +      -       +      +
    666A  LEU*     2.9    43.3    +      -       +      +
    733A  MET*     3.5    49.1    -      -       +      +
    736A  GLY      3.6    22.4    -      -       -      +
    737A  LEU*     3.8    20.9    -      -       +      +
    740A  ALA*     6.2     0.2    -      -       +      -
    789A  VAL*     6.5     0.2    -      -       +      -
    792A  MET*     4.3    10.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 663 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    579A  LEU*     3.2    37.0    -      -       +      -
    582A  LEU*     3.9    20.9    -      -       +      -
    586A  TRP*     4.2     8.3    -      -       +      -
    595A  ILE*     4.7     6.1    -      -       +      -
    659A  GLY      3.2    15.4    +      -       -      +
    660A  TYR*     3.6    13.9    -      -       +      +
    661A  CYS      3.3     0.2    -      -       -      -
    662A  LEU*     1.3    74.7    -      -       -      +
    664A  CYS*     1.3    65.3    +      -       -      +
    666A  LEU*     4.1     4.0    -      -       -      +
    667A  LEU*     3.0    41.1    +      -       +      +
    669A  VAL*     5.1     0.7    -      -       +      -
    690A  PHE*     4.4    14.4    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with CYS 664 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    660A  TYR*     2.8    24.2    +      -       -      +
    661A  CYS      3.5     4.9    -      -       -      +
    663A  VAL*     1.3    78.0    -      -       -      +
    665A  TYR*     1.3    57.4    +      -       -      +
    668A  GLN*     2.8     9.7    +      -       -      -
    669A  VAL*     2.7    52.2    +      -       +      +
    672A  ARG*     4.5     2.5    -      -       -      -
    687A  HIS*     3.9    29.8    -      -       -      -
    690A  PHE*     6.0     1.3    -      -       -      -
    708A  PHE*     3.6    33.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 665 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    661A  CYS*     2.9    13.4    +      -       -      +
    662A  LEU*     3.7     4.3    -      -       +      +
    664A  CYS*     1.3    74.5    -      -       -      +
    666A  LEU*     1.3    81.1    +      -       +      +
    668A  GLN*     2.8    44.4    +      -       -      +
    737A  LEU*     5.0    10.5    -      -       +      -
    775A  ARG*     3.1    36.2    +      -       +      +
    777A  HIS*     2.5    35.1    +      +       -      -
    788A  LEU*     4.5     6.2    -      -       +      +
    792A  MET*     3.5    46.9    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 666 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    578A  VAL*     6.3     1.1    -      -       +      -
    582A  LEU*     4.1    35.2    -      -       +      -
    586A  TRP*     5.5     1.6    -      -       +      -
    662A  LEU*     2.9    33.0    +      -       +      +
    663A  VAL*     4.1     2.9    -      -       -      +
    665A  TYR*     1.3    88.4    -      -       +      +
    667A  LEU*     1.3    60.9    +      -       +      +
    737A  LEU*     4.7    12.1    -      -       +      -
    740A  ALA*     4.9     6.5    -      -       +      -
    747A  VAL*     6.3     0.4    -      -       +      -
    772A  LEU*     3.2    13.7    -      -       +      +
    775A  ARG*     2.9    44.4    +      -       +      +
    776A  PHE*     4.1    36.3    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 667 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    574A  LEU*     6.0     2.0    -      -       +      -
    575A  ALA*     4.2    30.1    -      -       +      +
    578A  VAL*     4.4    31.0    -      -       +      -
    579A  LEU*     5.5     0.7    -      -       +      -
    582A  LEU*     6.2     0.4    -      -       +      -
    663A  VAL*     3.0    33.4    +      -       +      +
    666A  LEU*     1.3    79.8    -      -       +      +
    668A  GLN*     1.3    65.4    +      -       -      +
    669A  VAL*     3.9    13.2    -      -       +      -
    690A  PHE*     5.1     2.2    -      -       +      -
    693A  ILE*     3.4    16.8    -      -       +      +
    694A  LEU*     2.9    47.2    +      -       +      +
    751A  VAL*     5.1     7.4    -      -       +      -
    772A  LEU*     5.5     3.6    -      -       +      -
----------------------------------------------------------
 Back to top of page


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