Contacts of the helix formed by residues 52 - 79 (chain B) in PDB entry 1ZHH


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 52 (chain B).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     51B  ARG*     1.3    76.6    -      -       -      +
     53B  LYS*     1.3    68.1    +      -       +      +
     54B  GLN      3.2     2.6    +      -       -      -
     55B  GLN*     2.7    39.6    +      -       -      +
     56B  THR*     3.6    17.7    +      -       -      +
    251B  ILE*     4.8     2.3    -      -       +      +
    270B  GLN*     5.6     7.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 53 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     51B  ARG      3.1    28.4    -      -       -      +
     52B  THR*     1.3    83.2    -      -       +      +
     54B  GLN*     1.3    62.2    +      -       +      +
     56B  THR*     3.9     0.7    +      -       -      -
     57B  SER*     3.3    26.3    +      -       -      -
    251B  ILE*     4.1    36.9    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 54 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     51B  ARG*     3.6    22.4    +      -       -      +
     52B  THR      3.2     1.0    -      -       -      -
     53B  LYS*     1.3    79.0    -      -       +      +
     55B  GLN*     1.3    59.9    +      -       -      +
     57B  SER*     3.3     6.2    +      -       -      -
     58B  ALA*     3.1    28.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 55 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     51B  ARG      4.9     0.4    +      -       -      -
     52B  THR*     2.7    36.8    +      -       -      +
     54B  GLN*     1.3    79.0    -      -       -      +
     56B  THR*     1.3    66.5    +      -       -      +
     58B  ALA*     3.7     6.4    +      -       -      +
     59B  LEU*     3.2    23.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 56 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     52B  THR*     3.6    16.4    +      -       -      -
     53B  LYS      4.2     0.4    -      -       -      -
     54B  GLN      3.3     0.4    -      -       -      -
     55B  GLN*     1.3    81.1    -      -       -      +
     57B  SER*     1.3    64.6    +      -       -      +
     59B  LEU*     3.3     7.2    +      -       +      +
     60B  ILE*     3.2    28.8    +      -       +      +
    208B  VAL*     4.4    13.0    -      -       +      -
    251B  ILE*     4.0    10.3    -      -       +      -
    268B  THR*     3.9    20.6    -      -       +      +
    270B  GLN*     3.4    38.9    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 57 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     53B  LYS      3.3    18.5    +      -       -      -
     54B  GLN*     3.3     6.0    +      -       -      -
     56B  THR*     1.3    79.2    -      -       -      +
     58B  ALA*     1.3    60.0    +      -       -      +
     60B  ILE*     3.4     4.8    -      -       -      +
     61B  HIS*     3.2    25.5    +      -       -      +
    251B  ILE*     3.7     9.6    -      -       -      +
    252B  GLU      3.9     4.7    +      -       -      -
    253B  THR*     2.6    35.2    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 58 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     54B  GLN      3.1    16.6    +      -       -      +
     55B  GLN*     4.0     7.6    -      -       -      +
     56B  THR      3.3     0.2    -      -       -      -
     57B  SER*     1.3    75.7    -      -       -      +
     59B  LEU*     1.3    57.7    +      -       -      +
     61B  HIS*     4.0     5.0    -      -       -      +
     62B  ASN*     3.0    40.8    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 59 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     55B  GLN      3.2    18.3    +      -       -      +
     56B  THR*     3.7     8.5    -      -       +      +
     57B  SER      3.3     0.4    -      -       -      -
     58B  ALA*     1.3    76.4    -      -       -      +
     60B  ILE*     1.3    61.3    +      -       +      +
     62B  ASN*     3.1    13.9    +      -       +      +
     63B  ILE*     3.0    45.2    +      -       +      +
    205B  GLU      4.4     4.9    -      -       -      +
    206B  SER*     3.8    31.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 60 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     56B  THR*     3.2    16.8    +      -       +      +
     57B  SER*     3.4    11.2    -      -       -      +
     59B  LEU*     1.3    76.3    -      -       +      +
     61B  HIS*     1.3    61.1    +      -       -      +
     63B  ILE*     4.2     7.6    -      -       -      -
     64B  PHE*     2.9    27.2    +      -       -      +
    202B  LEU*     3.7    13.4    -      -       +      +
    206B  SER*     3.5    28.5    -      -       -      +
    208B  VAL*     5.0     0.4    -      -       +      -
    211B  VAL*     5.8     0.9    -      -       +      -
    253B  THR*     3.5    31.2    -      -       +      +
    266B  LEU*     3.9    23.1    -      -       +      +
    268B  THR*     3.5    35.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with HIS 61 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     57B  SER      3.2    15.0    +      -       -      +
     58B  ALA*     4.0     5.4    -      -       -      +
     60B  ILE*     1.3    81.3    -      -       -      +
     62B  ASN*     1.3    60.5    +      -       -      +
     64B  PHE*     4.1    14.5    -      +       -      +
     65B  ASP*     3.0    45.4    +      -       -      +
    253B  THR*     4.2    10.5    -      -       +      -
    254B  PRO      3.5    16.7    +      -       -      -
    255B  ILE*     3.7     9.8    -      -       +      -
    256B  VAL*     3.1    48.4    +      -       +      +
    257B  VAL*     5.4     0.4    -      -       +      -
    266B  LEU*     5.4     1.8    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 62 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     58B  ALA*     3.0    31.8    +      -       -      +
     59B  LEU*     3.1    13.3    +      -       +      +
     61B  HIS*     1.3    78.0    -      -       -      +
     63B  ILE*     1.3    60.0    +      -       +      +
     65B  ASP*     3.9     9.4    -      -       -      +
     66B  SER*     3.0    28.9    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 63 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     59B  LEU*     3.0    23.6    +      -       +      +
     60B  ILE*     3.8     7.9    -      -       -      +
     61B  HIS      3.3     0.2    -      -       -      -
     62B  ASN*     1.3    75.0    -      -       +      +
     64B  PHE*     1.3    65.4    +      -       -      +
     66B  SER*     2.8    21.1    +      -       -      +
     67B  HIS*     3.2    11.4    +      -       -      +
    198B  LEU*     5.9     0.8    -      -       +      +
    201B  LYS*     4.0    24.9    -      -       +      +
    202B  LEU*     4.0    15.7    -      -       +      +
    205B  GLU*     3.5    58.3    -      -       +      +
    206B  SER*     3.5    17.7    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 64 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     60B  ILE      2.9    18.1    +      -       -      +
     61B  HIS*     3.6    10.1    -      +       -      +
     63B  ILE*     1.3    78.2    -      -       -      +
     65B  ASP*     1.3    75.0    +      -       -      +
     67B  HIS*     3.2     9.9    +      -       -      +
     68B  PHE*     3.2    56.6    -      +       -      -
    168B  LEU*     5.1     6.3    -      -       +      -
    192B  LEU*     4.7    12.8    -      -       +      -
    198B  LEU*     4.9     8.5    -      -       +      -
    202B  LEU*     3.9    16.1    -      -       +      +
    213B  LEU*     5.1     5.6    -      -       +      -
    255B  ILE*     3.6    49.1    -      -       +      -
    257B  VAL*     4.9     7.9    -      -       +      -
    264B  LEU*     5.0     6.5    -      -       +      -
    266B  LEU*     4.2    16.6    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASP 65 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     61B  HIS*     3.0    46.9    +      -       -      +
     62B  ASN*     3.9    10.7    -      -       -      +
     63B  ILE      3.3     0.2    -      -       -      -
     64B  PHE*     1.3    82.6    -      -       -      +
     66B  SER*     1.3    56.1    +      -       -      +
     68B  PHE*     3.3     6.2    +      -       -      +
     69B  ALA*     2.9    31.4    +      -       +      +
    256B  VAL      4.8     2.4    -      -       -      +
    257B  VAL*     5.5     3.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 66 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     62B  ASN      3.0    15.9    +      -       -      -
     63B  ILE*     2.8    26.0    +      -       -      +
     65B  ASP*     1.3    74.4    -      -       -      +
     67B  HIS*     1.3    64.5    +      -       -      +
     69B  ALA*     4.0     6.2    -      -       -      +
     70B  ALA*     3.1    26.2    +      -       -      +
    110B  HIS*     4.2     4.6    +      -       -      -
    201B  LYS*     6.0     0.7    -      -       -      -
    205B  GLU*     4.8     4.3    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with HIS 67 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     63B  ILE      3.2     7.5    +      -       -      +
     64B  PHE      3.3    11.7    -      -       -      +
     66B  SER*     1.3    82.2    +      -       -      +
     68B  PHE*     1.3    80.7    +      +       +      +
     70B  ALA*     3.7     2.6    +      -       -      +
     71B  ILE*     3.3    45.7    +      -       +      +
    109B  SER      3.2    24.5    -      -       -      -
    110B  HIS*     3.8     9.9    -      +       -      -
    111B  THR      5.0     2.9    +      -       -      -
    113B  GLU*     5.7     2.0    +      -       -      -
    190B  VAL*     4.7     6.8    -      -       +      +
    195B  ASN*     5.5     2.6    +      -       -      -
    197B  ALA*     6.3     0.7    -      -       +      -
    198B  LEU*     3.9    33.4    -      -       +      +
    201B  LYS*     2.8    31.6    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 68 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     64B  PHE*     3.2    65.3    -      +       -      -
     65B  ASP*     3.3     7.8    +      -       -      +
     67B  HIS*     1.3    87.4    -      +       +      +
     69B  ALA*     1.3    60.4    +      -       -      +
     71B  ILE*     3.4     2.4    +      -       -      +
     72B  GLN*     2.8    30.4    +      -       -      +
    153B  TRP*     3.5    34.2    -      +       +      +
    168B  LEU*     3.6    28.3    -      -       +      -
    190B  VAL*     3.6    42.0    -      -       +      -
    192B  LEU*     4.0    11.0    -      -       +      -
    198B  LEU*     4.7     2.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 69 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     65B  ASP*     2.9    19.0    +      -       +      +
     66B  SER*     4.0     7.6    -      -       -      +
     68B  PHE*     1.3    76.5    -      -       -      +
     70B  ALA*     1.3    57.2    +      -       -      +
     72B  GLN*     3.4    13.2    +      -       -      +
     73B  ILE*     3.0    42.4    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 70 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     66B  SER      3.1    19.1    +      -       -      +
     67B  HIS      3.8     0.2    -      -       -      +
     69B  ALA*     1.3    75.3    -      -       -      +
     71B  ILE*     1.3    63.9    +      -       -      +
     73B  ILE*     3.3     9.3    +      -       -      +
     74B  HIS*     3.1    33.4    +      -       +      +
    107B  ASP*     5.0     0.4    -      -       -      +
    110B  HIS*     3.4    35.9    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 71 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     67B  HIS*     3.3    48.2    +      -       +      +
     68B  PHE*     3.8     5.6    -      -       -      +
     70B  ALA*     1.3    76.6    -      -       -      +
     72B  GLN*     1.3    56.6    +      -       -      +
     74B  HIS*     3.4     3.0    +      -       -      +
     75B  HIS*     2.9    28.5    +      -       +      +
    110B  HIS*     3.5    27.6    -      -       -      +
    111B  THR      3.8    16.6    -      -       -      +
    112B  PRO*     4.7    10.3    -      -       +      -
    153B  TRP*     3.9    18.8    -      -       +      -
    188B  ASN*     3.7    21.3    +      -       -      +
    190B  VAL*     4.0    15.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 72 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     68B  PHE      2.8    18.4    +      -       -      +
     69B  ALA*     3.5    13.0    -      -       -      +
     71B  ILE*     1.3    76.7    -      -       -      +
     73B  ILE*     1.3    69.5    +      -       -      +
     75B  HIS*     3.4     1.5    +      -       -      +
     76B  ASP*     2.9    56.3    +      -       -      +
    153B  TRP*     4.3    12.4    +      -       +      +
    170B  ARG*     3.3    38.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 73 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     69B  ALA*     3.0    30.7    +      -       +      +
     70B  ALA*     3.7     8.3    -      -       -      +
     71B  ILE      3.3     0.2    -      -       -      -
     72B  GLN*     1.3    88.7    -      -       -      +
     74B  HIS*     1.3    70.1    +      -       +      +
     76B  ASP*     3.5     4.6    +      -       -      +
     77B  SER*     3.2    24.5    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with HIS 74 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     70B  ALA*     3.1    25.7    +      -       -      +
     71B  ILE*     3.8     5.2    -      -       -      +
     73B  ILE*     1.3    79.3    -      -       +      +
     75B  HIS*     1.3    55.8    +      -       -      +
     77B  SER*     3.2     3.9    +      -       -      -
     78B  ASN*     2.7    53.2    +      -       -      +
    103B  ILE*     5.0    12.7    -      -       +      +
    106B  SER*     5.8     1.8    -      -       -      -
    107B  ASP*     2.7    38.9    +      -       +      -
    110B  HIS*     3.7    20.8    +      -       +      +
    115B  ARG*     6.1     0.9    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with HIS 75 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     71B  ILE      2.9    18.2    +      -       -      +
     72B  GLN*     3.6     5.8    -      -       -      +
     74B  HIS*     1.3    75.3    -      -       -      +
     76B  ASP*     1.3    57.6    +      -       -      +
     78B  ASN*     4.0     7.2    -      -       +      +
     79B  SER*     2.5    43.2    +      -       -      -
    170B  ARG*     3.1    46.2    +      -       +      +
    172B  VAL*     3.7    14.3    -      -       +      +
    186B  SER*     3.0    42.3    +      -       -      -
    188B  ASN*     3.5    33.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASP 76 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     72B  GLN*     2.9    42.0    +      -       -      +
     73B  ILE*     3.8     5.6    -      -       -      +
     75B  HIS*     1.3    78.2    -      -       -      +
     77B  SER*     1.3    61.6    +      -       -      +
     79B  SER*     3.5    10.0    +      -       -      -
     80B  LYS*     3.3    31.3    +      -       -      +
    151B  ASN*     4.6     2.8    -      -       -      +
    170B  ARG*     3.1    25.6    +      -       -      -
    172B  VAL*     3.4    18.4    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 77 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     73B  ILE*     3.2    16.9    +      -       -      -
     74B  HIS*     3.8     5.6    -      -       -      -
     76B  ASP*     1.3    76.0    -      -       -      +
     78B  ASN*     1.3    69.4    +      -       -      +
     79B  SER      3.1     1.6    -      -       -      -
     80B  LYS*     3.1    23.4    +      -       -      +
     81B  SER*     3.7     3.8    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 78 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     74B  HIS*     2.7    37.9    +      -       -      +
     75B  HIS*     4.1     7.6    -      -       +      +
     77B  SER*     1.3    76.6    +      -       -      +
     79B  SER*     1.3    57.6    +      -       -      +
     81B  SER*     3.0    28.5    -      -       -      -
     84B  ILE*     3.1    13.5    -      -       +      +
     99B  PHE*     4.7     2.9    -      -       +      -
    100B  PHE*     4.6    13.7    -      -       +      -
    103B  ILE*     3.5    47.0    -      -       +      +
    115B  ARG*     4.0    18.2    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 79 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     75B  HIS*     2.5    39.6    +      -       -      -
     76B  ASP      3.6     6.5    -      -       -      -
     77B  SER      3.1     0.6    -      -       -      -
     78B  ASN*     1.3    77.0    -      -       -      +
     80B  LYS*     1.3    59.0    +      -       -      +
     81B  SER      3.2     4.5    +      -       -      +
     84B  ILE*     4.2     4.9    -      -       -      +
    172B  VAL*     4.1    18.4    -      -       -      +
    173B  PRO      4.6     2.5    -      -       -      +
    174B  ILE*     3.6    39.8    -      -       -      +
    175B  LEU      4.9     2.8    +      -       -      +
    186B  SER*     3.9     9.5    +      -       -      -
----------------------------------------------------------
 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