Contacts of the helix formed by residues 54 - 79 (chain C) in PDB entry 3PL7


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 54 (chain C).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     55C  SER*     1.3    65.9    +      -       -      +
     56C  THR*     3.3    14.8    +      -       -      -
     57C  LYS*     3.6    27.2    +      -       +      +
     58C  LYS*     3.4    32.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 55 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    111A  GLN*     3.1    47.6    +      -       -      +
    112A  LEU*     4.0    11.8    -      -       -      +
     54C  ALA*     1.3    76.2    -      -       -      +
     56C  THR*     1.3    65.7    +      -       -      +
     58C  LYS*     3.8     7.7    +      -       -      +
     59C  LEU*     3.4    21.3    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 56 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    112A  LEU*     3.4    25.6    -      -       +      -
    122A  SER*     3.8    17.0    -      -       -      +
    125A  GLN*     2.8    40.7    +      -       -      +
    126A  VAL*     3.7    19.0    -      -       +      +
    129A  GLU*     5.2     0.8    -      -       -      +
     54C  ALA      3.9    11.3    +      -       -      +
     55C  SER*     1.3    80.6    +      -       -      +
     57C  LYS*     1.3    64.7    +      -       -      +
     59C  LEU*     3.8     1.8    -      -       -      +
     60C  SER*     3.2    25.3    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 57 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    129A  GLU*     4.6    16.4    -      -       +      -
     54C  ALA*     3.6    25.8    +      -       -      +
     55C  SER      3.3     0.4    -      -       -      -
     56C  THR*     1.3    79.0    +      -       -      +
     58C  LYS*     1.3    60.8    +      -       +      +
     60C  SER*     3.4     5.9    +      -       -      -
     61C  GLU*     2.8    44.2    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 58 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    111A  GLN*     4.8    14.2    +      -       -      +
     54C  ALA*     3.4    20.5    +      -       -      +
     55C  SER*     4.1     7.2    -      -       -      +
     56C  THR      3.4     0.2    -      -       -      -
     57C  LYS*     1.3    76.6    -      -       +      +
     59C  LEU*     1.3    57.8    +      -       -      +
     61C  GLU*     3.6     9.3    -      -       -      +
     62C  CYS*     2.9    29.8    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 59 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    108A  LEU*     3.5    51.4    -      -       +      +
    109A  THR*     4.4     1.1    -      -       +      -
    112A  LEU*     3.8    33.4    -      -       +      -
    126A  VAL*     4.5     4.7    -      -       +      -
    146A  PHE*     4.0    15.9    -      -       +      -
     55C  SER      3.4    15.8    +      -       -      +
     56C  THR*     3.8     5.4    -      -       -      +
     57C  LYS      3.2     0.2    -      -       -      -
     58C  LYS*     1.3    79.1    -      -       -      +
     60C  SER*     1.3    52.9    +      -       -      +
     62C  CYS*     3.1     8.6    +      -       +      +
     63C  LEU*     2.7    45.6    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 60 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    126A  VAL*     3.2    31.9    -      -       -      -
    129A  GLU*     2.9    29.7    +      -       -      +
    130A  LEU*     3.9     7.9    -      -       -      +
     56C  THR      3.2    15.4    +      -       -      -
     57C  LYS      3.4     4.0    +      -       -      -
     59C  LEU*     1.3    76.4    -      -       -      +
     61C  GLU*     1.3    58.7    +      -       -      +
     63C  LEU*     3.5    10.0    -      -       -      +
     64C  LYS*     2.7    37.9    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 61 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    129A  GLU*     4.9    10.7    +      -       -      +
    193B  GLU*     3.6    41.7    -      -       -      +
    194B  LEU*     3.3    30.6    -      -       +      +
     57C  LYS*     2.8    35.0    +      -       +      +
     58C  LYS*     3.6     9.2    -      -       -      +
     60C  SER*     1.3    78.4    +      -       -      +
     62C  CYS*     1.3    56.2    +      -       -      +
     64C  LYS*     3.7     8.4    -      -       -      +
     65C  ARG*     3.0    26.8    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with CYS 62 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    104A  ALA*     4.1    13.7    -      -       -      -
    108A  LEU*     4.9    12.1    -      -       -      -
     58C  LYS      2.9    14.7    +      -       -      +
     59C  LEU*     3.2    11.9    -      -       +      +
     61C  GLU*     1.3    76.1    -      -       -      +
     63C  LEU*     1.3    63.6    +      -       -      +
     65C  ARG*     3.1    30.6    +      -       -      +
     66C  ILE*     3.0    48.4    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 63 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97A  PHE*     4.7    12.6    -      -       +      -
    105A  PHE*     4.8     3.6    -      -       +      -
    108A  LEU*     4.0    29.8    -      -       +      -
    126A  VAL*     3.7    29.8    -      -       +      -
    130A  LEU*     4.1    16.3    -      -       +      +
    142A  ALA*     3.8    28.8    -      -       +      +
    146A  PHE*     3.8    24.0    -      -       +      -
     59C  LEU*     2.7    22.7    +      -       +      +
     60C  SER*     3.5     6.1    -      -       -      +
     62C  CYS*     1.3    74.5    -      -       -      +
     64C  LYS*     1.3    61.1    +      -       -      +
     66C  ILE*     3.5     4.5    +      -       +      +
     67C  GLY*     3.0    20.3    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 64 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    129A  GLU*     3.7    30.0    +      -       -      +
    130A  LEU*     3.7    22.3    -      -       +      +
    132A  ARG*     5.5     1.8    -      -       -      +
    133A  ASP*     3.6    26.1    +      -       -      +
    139A  ARG*     3.4    37.9    -      -       -      +
    194B  LEU*     4.9    19.7    -      -       +      -
     60C  SER      2.7    22.5    +      -       -      +
     61C  GLU*     3.7     9.2    -      -       -      +
     63C  LEU*     1.3    73.4    -      -       -      +
     65C  ARG*     1.3    62.3    +      -       -      +
     68C  ASP*     3.0    34.5    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 65 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    101A  TYR*     6.2     0.8    -      -       -      -
    104A  ALA*     5.5     2.8    -      -       -      +
    138B  GLY*     6.5     0.2    -      -       -      -
    194B  LEU*     3.1    37.0    +      -       +      +
    195B  TYR*     3.5    52.6    +      -       +      +
     61C  GLU*     3.0    20.2    +      -       -      +
     62C  CYS*     3.1    41.5    +      -       -      +
     64C  LYS*     1.3    75.7    -      -       -      +
     66C  ILE*     1.3    70.4    +      -       -      +
     68C  ASP*     4.0     3.8    -      -       -      +
     69C  GLU*     3.2    28.2    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 66 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97A  PHE*     2.9    38.4    -      -       +      -
    101A  TYR*     3.2    61.3    +      -       +      -
    104A  ALA*     3.9    10.3    -      -       +      -
    105A  PHE*     5.3     3.4    -      -       +      -
    108A  LEU*     5.9     0.4    -      -       +      -
     62C  CYS*     3.0    40.5    +      -       -      +
     63C  LEU*     3.9     4.3    -      -       +      +
     65C  ARG*     1.3    84.4    -      -       -      +
     67C  GLY*     1.3    59.3    +      -       -      +
     69C  GLU*     3.0     5.1    +      -       -      +
     70C  LEU*     2.9    26.5    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 67 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97A  PHE*     3.8    10.5    -      -       -      -
    138A  GLY*     3.5    30.9    -      -       -      -
    139A  ARG*     4.3     2.2    -      -       -      -
    142A  ALA*     4.6     0.7    -      -       -      -
     63C  LEU      3.0    16.7    +      -       -      -
     64C  LYS      4.1     0.2    -      -       -      -
     66C  ILE*     1.3    76.1    -      -       -      +
     68C  ASP*     1.3    57.8    +      -       -      +
     70C  LEU*     3.5     2.5    +      -       -      +
     71C  ASP*     2.8    31.4    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASP 68 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    136A  ASN*     2.8    17.0    +      -       -      +
    139A  ARG*     2.7    44.8    +      -       -      +
    136B  ASN*     3.4    33.4    +      -       -      +
    137B  TRP*     4.9     0.7    +      -       -      +
    138B  GLY*     4.2     8.9    +      -       -      +
    139B  ARG*     5.1     0.2    -      -       -      +
    194B  LEU*     5.7     2.8    -      -       -      +
     64C  LYS*     3.0    24.7    +      -       -      +
     65C  ARG*     4.0     4.9    -      -       -      +
     67C  GLY*     1.3    74.8    -      -       -      +
     69C  GLU*     1.3    57.9    +      -       -      +
     71C  ASP*     3.6     6.6    +      -       -      +
     72C  SER*     2.7    31.9    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 69 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    101A  TYR*     2.8    33.0    +      -       -      +
     93B  ALA*     4.9     3.5    -      -       -      +
     96B  GLU*     6.0     1.7    -      -       -      +
     97B  PHE*     4.0    34.0    +      -       +      -
    100B  ARG*     4.5     6.2    +      -       -      -
    101B  TYR*     4.1     5.4    +      -       +      -
    138B  GLY*     4.3     5.2    -      -       -      +
    141B  VAL*     4.6     3.9    -      -       +      +
    195B  TYR*     2.8    42.5    +      -       -      +
     65C  ARG*     3.2    15.4    +      -       -      +
     66C  ILE*     3.0     6.6    +      -       -      +
     68C  ASP*     1.3    74.5    -      -       -      +
     70C  LEU*     1.3    66.8    +      -       -      +
     72C  SER*     3.0    17.2    +      -       -      -
     73C  ASN*     3.0    14.2    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 70 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     93A  ALA*     4.4     6.5    -      -       +      +
     96A  GLU*     3.8    31.9    -      -       +      +
     97A  PHE*     3.8    34.8    -      -       +      -
    100A  ARG*     4.0     8.1    -      -       -      +
    101A  TYR*     4.6     3.8    -      -       +      -
    138A  GLY*     5.2     2.2    -      -       -      -
    141A  VAL*     4.3    13.5    -      -       +      -
    195A  TYR*     4.3    17.9    -      -       +      -
    101B  TYR*     3.6    20.9    +      -       +      +
     66C  ILE      2.9    15.4    +      -       -      +
     67C  GLY*     3.7     6.3    -      -       -      +
     69C  GLU*     1.3    73.8    -      -       -      +
     71C  ASP*     1.3    61.5    +      -       -      +
     73C  ASN*     3.2     4.2    +      -       -      +
     74C  MET*     2.9    38.8    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASP 71 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    136A  ASN*     3.7    25.3    +      -       -      +
    137A  TRP*     3.8    11.3    +      -       -      +
    138A  GLY*     3.6     5.9    +      -       -      -
    195A  TYR*     2.8    28.6    +      -       -      +
    136B  ASN*     4.9     0.2    +      -       -      -
    139B  ARG*     2.8    36.1    +      -       -      -
     67C  GLY      2.8    21.4    +      -       -      +
     68C  ASP*     3.7     4.9    -      -       -      +
     70C  LEU*     1.3    70.5    -      -       -      +
     72C  SER*     1.3    65.3    +      -       -      +
     74C  MET*     3.5     2.6    +      -       -      +
     75C  GLU*     3.3    21.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 72 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97B  PHE*     4.1     5.2    -      -       -      -
    130B  LEU*     4.3     2.4    -      -       -      +
    138B  GLY      3.1    24.8    -      -       -      -
    139B  ARG*     3.2    15.5    +      -       -      +
    142B  ALA*     3.9    21.3    -      -       -      -
     68C  ASP      2.7    22.9    +      -       -      -
     69C  GLU*     3.1    10.8    -      -       -      -
     71C  ASP*     1.3    74.7    +      -       -      +
     73C  ASN*     1.3    63.9    +      -       -      +
     75C  GLU*     3.1    16.7    +      -       -      +
     76C  LEU*     3.1    17.6    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 73 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    100A  ARG*     4.1     6.5    -      -       -      +
     97B  PHE*     4.8     0.7    -      -       +      -
    101B  TYR*     3.1    50.6    -      -       +      +
    103B  ARG*     4.6     1.4    +      -       -      +
    104B  ALA*     3.5    22.5    -      -       -      +
     69C  GLU      3.0     7.8    +      -       -      +
     70C  LEU      3.2     6.3    +      -       -      +
     72C  SER*     1.3    76.3    -      -       -      +
     74C  MET*     1.3    72.8    +      -       -      +
     75C  GLU      3.0     0.2    -      -       -      -
     76C  LEU*     3.0    28.0    +      -       -      +
     77C  GLN*     2.9    38.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with MET 74 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     93A  ALA*     6.4     0.2    -      -       -      -
     96A  GLU*     3.4    30.7    -      -       -      +
    194A  LEU*     4.4    17.8    -      -       +      +
    195A  TYR*     3.4    62.8    -      -       +      +
     70C  LEU*     2.9    21.9    +      -       +      +
     71C  ASP      3.9     3.4    -      -       -      +
     72C  SER      3.3     0.2    -      -       -      -
     73C  ASN*     1.3   101.6    -      -       -      +
     75C  GLU*     1.3    58.9    +      -       -      +
     77C  GLN*     3.9    22.5    +      -       -      +
     78C  ARG*     3.5    18.5    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 75 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    129B  GLU      4.0     7.2    -      -       -      +
    130B  LEU*     4.0    23.6    -      -       +      +
    133B  ASP*     3.8    18.9    -      -       -      +
    139B  ARG*     4.4    13.9    +      -       -      +
     71C  ASP*     3.3    12.1    +      -       -      +
     72C  SER*     3.2    12.3    -      -       -      +
     73C  ASN      3.0     0.4    -      -       -      -
     74C  MET*     1.3    76.9    -      -       -      +
     76C  LEU*     1.3    63.6    +      -       -      +
     77C  GLN      3.2     1.6    -      -       -      -
     78C  ARG*     2.7    56.2    +      -       -      +
     79C  MET*     3.2    31.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 76 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97B  PHE*     4.1    25.1    -      -       +      -
    101B  TYR*     5.4     0.2    -      -       +      -
    104B  ALA*     4.0    20.0    -      -       +      -
    105B  PHE*     4.1    24.5    -      -       +      -
    108B  LEU*     3.5    40.4    -      -       +      +
    130B  LEU*     4.5    22.9    -      -       +      -
    142B  ALA*     4.8     4.7    -      -       +      +
    146B  PHE*     5.2     6.3    -      -       +      -
     72C  SER      3.1    12.4    +      -       -      +
     73C  ASN*     3.0    22.6    +      -       -      +
     75C  GLU*     1.3    76.4    -      -       -      +
     77C  GLN*     1.3    62.0    +      -       -      +
     79C  MET*     3.4    20.8    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 77 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     96A  GLU*     5.6     0.2    +      -       -      -
    100A  ARG*     4.9     1.4    -      -       -      +
    194A  LEU      5.1     3.1    -      -       -      +
    103B  ARG*     2.7    46.2    -      -       -      +
    104B  ALA*     4.4     4.9    -      -       +      -
    108B  LEU*     5.6     0.4    -      -       -      -
     73C  ASN*     2.9    42.5    +      -       -      +
     74C  MET*     3.9    27.4    -      -       -      +
     76C  LEU*     1.3    78.7    -      -       -      +
     78C  ARG*     1.3    61.2    +      -       -      +
     79C  MET      3.0     9.9    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 78 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    194A  LEU*     4.1    27.0    -      -       +      +
    129B  GLU*     3.4    37.2    +      -       -      +
    132B  ARG*     5.6     5.0    -      -       -      +
    133B  ASP*     6.0     1.3    -      -       -      -
     74C  MET      3.5    14.0    +      -       -      +
     75C  GLU*     2.7    44.9    +      -       -      +
     77C  GLN*     1.3    78.0    -      -       -      +
     79C  MET*     1.3    65.0    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with MET 79 (chain C). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    108B  LEU*     3.7    31.9    -      -       +      +
    111B  GLN*     3.9    18.2    -      -       -      +
    112B  LEU*     6.5     0.7    -      -       +      -
    126B  VAL*     4.5    15.7    -      -       -      +
    129B  GLU*     3.9    18.6    -      -       +      -
    130B  LEU*     3.6    41.7    -      -       +      +
     75C  GLU*     3.2    31.6    -      -       +      +
     76C  LEU*     3.6    18.6    -      -       +      +
     77C  GLN      3.0    10.8    +      -       -      +
     78C  ARG*     1.3    85.9    -      -       -      +
----------------------------------------------------------
 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