Contacts of the helix formed by residues 154 - 176 (chain A) in PDB entry 1W4Z


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 154 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     95A  GLY      3.8     7.0    -      -       -      -
     96A  GLY*     4.2     0.4    -      -       -      -
    151A  VAL*     2.9    36.6    +      -       +      +
    152A  VAL      4.1     0.4    -      -       -      +
    153A  HIS*     1.3    79.0    -      -       -      +
    155A  ALA*     1.3    60.6    +      -       -      +
    156A  PRO*     3.4     4.3    -      -       -      -
    157A  TYR*     3.1     5.4    +      -       +      -
    158A  SER*     2.8    26.9    +      -       -      -
   1265A  FMT      3.8    26.7    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 155 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97A  GLY      5.4     0.2    +      -       -      -
     99A  THR*     3.5    25.7    +      -       +      +
    107A  TRP*     4.1     2.4    -      -       +      -
    151A  VAL      4.1     0.6    +      -       -      -
    153A  HIS      3.8     1.4    -      -       -      -
    154A  ALA*     1.3    77.8    -      -       -      +
    156A  PRO*     1.3    65.6    -      -       +      +
    158A  SER*     3.5     1.4    +      -       -      -
    159A  ALA*     2.8    31.0    +      -       -      +
    167B  PHE*     3.9    27.6    -      -       +      -
    170B  ALA*     3.8    18.6    -      -       +      +
    171B  LEU*     5.0     3.4    -      -       +      +
    174B  GLU*     4.9     1.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PRO 156 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     95A  GLY      3.9    13.9    -      -       -      +
     97A  GLY      5.8     0.2    -      -       -      +
     99A  THR*     5.4     0.2    -      -       -      +
    102A  LEU*     3.6    39.5    -      -       +      -
    106A  LEU*     5.3     1.3    -      -       +      -
    107A  TRP*     3.5    33.4    -      -       +      +
    110A  VAL*     3.5    23.0    -      -       +      +
    111A  VAL*     4.5     2.6    -      -       +      +
    154A  ALA*     3.4     2.9    -      -       -      -
    155A  ALA*     1.3    97.6    -      -       +      +
    157A  TYR*     1.3    54.1    +      -       -      +
    159A  ALA*     3.8     0.3    -      -       -      +
    160A  SER*     2.7    37.1    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 157 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     93A  ARG      3.5    25.1    -      -       -      -
     94A  PRO*     3.7    12.1    -      -       +      -
     95A  GLY      3.6    16.6    +      -       -      +
    110A  VAL*     3.8     4.0    -      -       -      +
    114A  ASN*     3.9     3.4    -      -       -      -
    144A  SER*     3.2    26.9    +      -       -      -
    146A  GLY*     4.6     5.4    -      -       -      -
    151A  VAL*     5.0     2.9    -      -       +      -
    154A  ALA*     3.1    13.1    +      -       +      +
    156A  PRO*     1.3    78.8    -      -       -      +
    158A  SER*     1.3    67.8    +      -       -      +
    160A  SER*     2.8     6.6    +      -       -      -
    161A  LYS*     2.8    55.6    +      -       +      +
   1262A  NAP      3.4    25.0    +      -       -      -
   1264A  FMT      3.2    25.0    +      -       -      -
   1265A  FMT      3.7    18.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 158 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    146A  GLY      3.2    19.7    +      -       -      +
    149A  GLN      3.4     4.5    +      -       -      -
    150A  GLY*     4.4     0.2    -      -       -      -
    151A  VAL*     3.1    33.1    +      -       -      +
    154A  ALA      2.8    16.2    +      -       -      -
    155A  ALA      3.9     3.1    -      -       -      -
    157A  TYR*     1.3    75.4    -      -       -      +
    159A  ALA*     1.3    59.0    +      -       -      +
    162A  HIS*     2.9    37.4    +      -       -      -
    166B  GLY*     4.0    16.6    -      -       -      -
    170B  ALA*     4.0     7.2    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 159 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    107A  TRP*     3.7    26.0    -      -       +      -
    111A  VAL*     5.5     0.4    -      -       +      -
    155A  ALA      2.8    22.7    +      -       -      +
    156A  PRO      3.8     1.6    -      -       -      +
    158A  SER*     1.3    73.5    -      -       -      +
    160A  SER*     1.3    64.0    +      -       -      +
    163A  GLY*     3.0    19.1    +      -       -      -
    115B  LEU*     4.1    10.9    -      -       +      +
    163B  GLY*     3.4    32.6    -      -       -      +
    166B  GLY*     4.3     0.8    -      -       -      -
    167B  PHE*     4.0     7.6    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 160 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    110A  VAL*     3.7    10.9    -      -       -      +
    111A  VAL*     4.2    14.8    -      -       -      +
    114A  ASN*     3.1    36.7    +      -       -      -
    115A  LEU*     3.9    14.5    -      -       -      +
    156A  PRO      2.7    19.9    +      -       -      -
    157A  TYR*     2.8    17.7    +      -       -      -
    159A  ALA*     1.3    73.9    -      -       -      +
    161A  LYS*     1.3    55.6    +      -       -      +
    163A  GLY*     3.1     4.2    +      -       -      -
    164A  VAL*     3.0    29.0    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 161 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     91A  ALA      5.3     0.6    +      -       -      -
     92A  GLY*     4.6     1.8    -      -       -      -
    114A  ASN*     4.0    21.0    +      -       +      +
    142A  ILE      3.2    16.1    +      -       -      +
    143A  ALA*     3.4    24.6    +      -       -      +
    144A  SER*     3.8    12.1    -      -       -      +
    146A  GLY      4.1     0.7    -      -       -      -
    147A  GLY*     3.6    21.9    -      -       -      +
    157A  TYR*     2.8    44.8    +      -       +      +
    158A  SER      4.0     0.9    -      -       -      +
    160A  SER*     1.3    72.2    +      -       -      +
    162A  HIS*     1.3    65.6    +      -       -      +
    164A  VAL*     2.9    21.3    +      -       +      +
    165A  VAL*     3.1    15.2    +      -       -      +
   1262A  NAP      2.8    43.8    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with HIS 162 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    146A  GLY      3.0    25.6    +      -       -      -
    147A  GLY      3.2    31.0    +      -       -      -
    148A  LYS*     3.3    21.9    +      -       -      -
    149A  GLN      3.5     7.1    +      -       -      -
    158A  SER*     2.9    21.5    +      -       -      +
    159A  ALA      3.8     2.0    -      -       -      +
    161A  LYS*     1.3    75.0    -      -       -      +
    163A  GLY*     1.3    65.2    +      -       -      +
    165A  VAL*     3.0     5.2    +      -       -      +
    166A  GLY      2.8    18.5    +      -       -      -
    261A  TYR*     4.9     1.6    -      -       -      -
    162B  HIS*     3.3    31.9    +      -       +      +
    165B  VAL*     4.4     4.6    -      -       +      +
    166B  GLY*     3.4    27.2    +      -       -      -
    169B  LYS*     3.7    22.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 163 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    115A  LEU*     3.5    15.7    -      -       -      +
    159A  ALA      3.0    15.4    +      -       -      -
    160A  SER      3.4     4.9    -      -       -      -
    161A  LYS      3.1     0.4    -      -       -      -
    162A  HIS*     1.3    78.1    -      -       -      +
    164A  VAL*     1.3    55.6    +      -       -      +
    166A  GLY*     3.1     1.2    +      -       -      -
    167A  PHE*     2.8    31.2    +      -       -      +
    159B  ALA*     3.3    27.8    -      -       -      -
    162B  HIS*     4.2     0.2    -      -       -      -
    163B  GLY      4.1     0.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 164 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    114A  ASN      3.1    28.3    -      -       -      +
    115A  LEU*     4.2     8.3    -      -       +      -
    118A  VAL*     4.0    15.0    -      -       +      -
    141A  ASN*     3.8    31.0    -      -       +      +
    142A  ILE      4.7     3.6    -      -       -      +
    143A  ALA*     4.0    20.6    -      -       +      -
    160A  SER      3.0    14.5    +      -       -      +
    161A  LYS*     2.9    20.2    +      -       +      +
    163A  GLY*     1.3    74.6    -      -       -      +
    165A  VAL*     1.3    53.7    +      -       -      +
    167A  PHE*     3.4     5.1    +      -       -      +
    168A  THR*     2.7    37.8    +      -       -      +
    184A  ALA*     5.0     0.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 165 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    143A  ALA*     4.0    18.8    -      -       +      -
    147A  GLY      3.9    20.6    -      -       -      +
    148A  LYS*     4.9     5.4    -      -       +      -
    161A  LYS      3.1    10.9    +      -       -      +
    162A  HIS*     3.0     8.4    +      -       -      +
    164A  VAL*     1.3    74.7    -      -       -      +
    166A  GLY*     1.3    66.9    +      -       -      +
    168A  THR*     3.0     8.6    +      -       -      -
    169A  LYS*     2.9    43.2    +      -       +      +
    184A  ALA*     4.7     2.0    -      -       +      -
    186A  CYS*     4.4     6.5    -      -       -      -
    251A  ALA*     4.0    29.6    -      -       +      -
    162B  HIS*     4.4     8.1    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 166 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    162A  HIS      2.8    11.3    +      -       -      -
    163A  GLY      3.6     2.5    -      -       -      -
    165A  VAL*     1.3    76.7    -      -       -      +
    167A  PHE*     1.3    61.9    +      -       -      +
    169A  LYS*     3.2     4.0    +      -       -      +
    170A  ALA*     3.0    24.1    +      -       -      +
    150B  GLY*     4.6     0.2    -      -       -      -
    158B  SER*     3.9    11.1    -      -       -      -
    159B  ALA      4.4     0.4    -      -       -      -
    162B  HIS*     3.3    38.0    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 167 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    115A  LEU*     4.7     4.5    -      -       +      -
    118A  VAL*     3.8    30.5    -      -       +      -
    119A  PHE*     4.0    15.7    -      +       -      -
    122A  THR*     4.1    14.6    -      -       +      -
    141A  ASN*     4.3     9.4    -      -       -      -
    163A  GLY      2.8    20.1    +      -       -      +
    164A  VAL*     3.6     6.5    -      -       -      +
    166A  GLY*     1.3    73.0    -      -       -      +
    168A  THR*     1.3    59.3    +      -       -      +
    170A  ALA*     3.9     1.2    -      -       -      +
    171A  LEU*     2.9    56.9    +      -       +      +
    182A  VAL*     5.7     0.4    -      -       +      -
     99B  THR*     3.9    22.9    -      -       +      -
    107B  TRP*     3.8    32.8    -      +       -      -
    155B  ALA*     3.9    16.2    -      -       +      -
    159B  ALA*     4.0    11.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 168 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    141A  ASN*     2.9    21.0    +      -       -      +
    164A  VAL      2.7    23.7    +      -       -      -
    165A  VAL*     3.0     8.5    +      -       -      -
    167A  PHE*     1.3    78.3    -      -       -      +
    169A  LYS*     1.3    64.0    +      -       +      +
    172A  GLY*     3.0    22.0    +      -       -      -
    182A  VAL*     3.8    15.1    -      -       +      +
    183A  ASN*     3.4    39.3    -      -       -      +
    184A  ALA*     3.6    13.7    -      -       +      +
    249A  ALA*     4.0     3.9    -      -       -      -
    250A  GLN      4.0     6.7    -      -       -      +
    251A  ALA*     6.0     0.4    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 169 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    148A  LYS*     6.3     0.4    -      -       -      +
    165A  VAL*     2.9    37.2    +      -       +      +
    166A  GLY      3.2     3.8    +      -       -      +
    168A  THR*     1.3    78.1    -      -       +      +
    170A  ALA*     1.3    63.8    +      -       -      +
    172A  GLY*     3.2     1.4    +      -       -      -
    173A  LEU*     3.0    29.4    +      -       +      +
    249A  ALA*     3.5    29.9    -      -       +      +
    250A  GLN*     5.2     0.9    -      -       -      +
    251A  ALA*     4.8    12.4    -      -       +      +
    261A  TYR*     5.7     4.6    -      -       -      -
    148B  LYS      3.9    17.7    +      -       -      +
    149B  GLN*     4.6     1.1    -      -       -      -
    150B  GLY*     3.8    20.4    -      -       -      +
    162B  HIS*     4.3    11.5    -      -       +      -
    261B  TYR*     3.9    13.3    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 170 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    166A  GLY      3.0    16.0    +      -       -      +
    167A  PHE      3.9     1.6    -      -       -      +
    169A  LYS*     1.3    77.6    -      -       -      +
    171A  LEU*     1.3    57.8    +      -       -      +
    173A  LEU*     3.4     3.4    +      -       -      +
    174A  GLU*     2.9    29.2    +      -       -      +
    150B  GLY*     3.5     9.7    -      -       -      -
    151B  VAL      3.7    29.8    -      -       -      +
    152B  VAL*     4.4     4.3    -      -       -      -
    153B  HIS      5.8     0.2    -      -       -      -
    155B  ALA*     3.8    24.5    -      -       +      +
    158B  SER*     3.9     4.0    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 171 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    122A  THR*     3.6    31.2    -      -       +      -
    126A  LEU*     4.2     7.9    -      -       +      -
    139A  ILE*     4.3     5.6    -      -       +      -
    167A  PHE*     2.9    34.4    +      -       +      +
    168A  THR      4.4     1.3    -      -       -      +
    170A  ALA*     1.3    73.5    -      -       -      +
    172A  GLY*     1.3    66.7    +      -       -      +
    174A  GLU*     3.0    16.5    +      -       -      +
    175A  LEU*     2.9    51.1    +      -       +      +
    182A  VAL*     4.3    10.3    -      -       +      -
     99B  THR*     3.5    33.2    -      -       +      +
    155B  ALA*     5.0     1.2    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 172 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    168A  THR      3.0    19.5    +      -       -      -
    169A  LYS      3.6     0.7    -      -       -      -
    171A  LEU*     1.3    78.5    -      -       -      +
    173A  LEU*     1.3    56.6    +      -       -      +
    175A  LEU      3.2     1.6    +      -       -      -
    176A  ALA*     2.9    29.7    +      -       -      +
    180A  ILE      5.2     0.2    -      -       -      +
    182A  VAL*     3.7    20.5    -      -       -      +
    248A  THR*     4.0    12.6    +      -       -      -
    249A  ALA*     4.1    10.1    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 173 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    169A  LYS*     3.0    17.6    +      -       +      +
    170A  ALA      3.9     2.5    -      -       -      +
    172A  GLY*     1.3    75.5    -      -       -      +
    174A  GLU*     1.3    63.2    +      -       -      +
    175A  LEU      3.3     0.3    +      -       -      -
    176A  ALA*     3.4    20.2    +      -       +      +
    177A  ARG      5.2     0.2    +      -       -      -
    248A  THR*     5.9     2.0    -      -       +      -
    249A  ALA*     4.1    14.8    -      -       +      +
    149B  GLN*     6.1     0.2    -      -       +      -
    150B  GLY*     3.5    35.4    -      -       -      +
    152B  VAL*     3.7    25.4    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 174 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    170A  ALA      2.9    16.2    +      -       -      +
    171A  LEU*     3.0    16.8    +      -       -      +
    173A  LEU*     1.3    79.5    -      -       -      +
    175A  LEU*     1.3    69.2    +      -       +      +
    176A  ALA      3.4     0.4    +      -       -      -
    177A  ARG      5.3     0.5    +      -       -      -
     98B  ALA*     3.5    10.6    -      -       -      +
     99B  THR*     2.6    46.4    +      -       -      -
    100B  ALA      4.8     0.7    +      -       -      -
    152B  VAL*     3.9    20.1    -      -       +      +
    153B  HIS*     3.9    34.6    +      -       +      +
    155B  ALA*     4.9     1.9    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 175 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    126A  LEU*     4.0    15.9    -      -       +      -
    132A  LEU*     4.0    26.7    -      -       +      -
    139A  ILE*     4.5     0.4    -      -       +      -
    171A  LEU*     2.9    44.6    +      -       +      +
    172A  GLY      3.6     2.2    -      -       -      +
    174A  GLU*     1.3    92.3    -      -       +      +
    176A  ALA*     1.3    64.2    +      -       -      +
    177A  ARG      3.2     2.7    -      -       -      -
    178A  THR*     2.8    42.1    +      -       +      +
    180A  ILE*     3.4    34.1    -      -       +      +
    182A  VAL*     3.9     8.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 176 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    172A  GLY      2.9    14.9    +      -       -      +
    173A  LEU*     3.4    20.3    +      -       +      +
    174A  GLU      3.4     0.6    -      -       -      -
    175A  LEU*     1.3    78.9    -      -       -      +
    177A  ARG*     1.3    60.2    +      -       +      +
    178A  THR      3.3     3.1    +      -       -      -
    179A  GLY*     4.2     4.9    +      -       -      -
    180A  ILE      4.7     4.8    -      -       -      +
    248A  THR*     4.5    17.7    -      -       +      +
----------------------------------------------------------
 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