Contacts of the helix formed by residues 223 - 244 (chain A) in PDB entry 5YL4


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 223 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    221A  ARG      3.5     6.5    +      -       -      +
    222A  PRO*     1.3    73.3    -      -       -      +
    224A  TYR*     1.3    66.9    +      -       -      +
    225A  THR*     3.6    12.9    +      -       -      -
    226A  ASN*     2.7    37.4    +      -       -      +
    227A  LEU*     3.1    28.0    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 224 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     11A  GLN*     4.0    10.7    +      -       -      -
     15A  GLN*     4.2    11.9    -      -       -      +
    177A  VAL*     2.9    29.9    +      -       +      -
    178A  SER*     4.8     0.3    -      -       -      -
    206A  ASN*     4.5     0.4    -      -       -      -
    223A  THR*     1.3    73.7    -      -       -      +
    225A  THR*     1.3    52.5    +      -       -      +
    227A  LEU*     3.9    16.6    -      -       +      -
    228A  ASN*     2.7    43.4    +      -       -      +
    501A  GTP      3.1    82.3    +      +       -      +
    245B  GLN*     5.0    21.3    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 225 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    223A  THR*     3.1    12.0    +      -       -      -
    224A  TYR*     1.3    78.8    -      -       -      +
    226A  ASN*     1.3    63.7    +      -       -      +
    228A  ASN*     4.1     4.2    -      -       -      +
    229A  ARG*     3.1    53.5    +      -       +      +
    245B  GLN*     5.4     3.8    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 226 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    213A  CYS*     3.8    18.9    -      -       +      -
    217A  LEU*     5.2     2.6    -      -       +      +
    219A  ILE*     3.8    19.5    -      -       +      +
    221A  ARG      4.5     0.5    -      -       -      +
    222A  PRO*     3.5     8.6    -      -       +      +
    223A  THR*     2.7    39.6    +      -       -      +
    225A  THR*     1.3    80.9    -      -       -      +
    227A  LEU*     1.3    61.4    +      -       -      +
    229A  ARG*     4.2     2.5    -      -       -      +
    230A  LEU*     3.4    19.6    +      -       -      +
    367A  ASP*     2.8    40.2    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 227 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    177A  VAL*     4.4    23.1    -      -       +      -
    206A  ASN*     4.5    12.6    -      -       -      +
    209A  ILE*     3.5    29.7    -      -       +      +
    210A  TYR*     3.5    31.2    -      -       +      +
    213A  CYS*     4.2     5.8    -      -       -      -
    222A  PRO*     4.2     7.6    -      -       +      +
    223A  THR      3.1    20.1    +      -       -      +
    224A  TYR*     3.8    26.5    -      -       +      +
    226A  ASN*     1.3    79.4    -      -       -      +
    228A  ASN*     1.3    59.0    +      -       -      +
    230A  LEU*     3.4     4.2    +      -       -      +
    231A  ILE*     2.8    39.9    +      -       +      +
    501A  GTP      4.5     2.7    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 228 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     15A  GLN*     3.5    22.6    +      -       -      +
     16A  ILE*     3.2    18.6    -      -       +      +
     19A  ALA*     3.7    16.2    -      -       +      +
    224A  TYR*     2.7    29.2    +      -       -      +
    225A  THR*     4.1     4.6    -      -       -      +
    227A  LEU*     1.3    69.9    -      -       -      +
    229A  ARG*     1.3    54.2    +      -       +      +
    231A  ILE*     3.6     5.9    -      -       -      +
    232A  SER*     2.6    38.0    +      -       -      -
    501A  GTP      2.7    48.1    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 229 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     19A  ALA*     4.7     9.9    +      -       +      +
     22A  GLU*     2.6    39.4    +      -       -      -
     23A  LEU*     5.3     0.3    -      -       -      +
    225A  THR*     3.1    41.2    +      -       +      +
    226A  ASN*     4.2     3.8    -      -       -      +
    228A  ASN*     1.3    76.7    -      -       +      +
    230A  LEU*     1.3    60.1    +      -       -      +
    232A  SER*     3.0    16.6    +      -       -      -
    233A  GLN*     3.3    19.2    +      -       -      +
    363A  VAL*     3.8    29.8    -      -       +      +
    365A  GLY      5.8     0.4    +      -       -      -
    366A  GLY*     5.0    15.2    -      -       -      -
    367A  ASP*     4.8    12.8    -      -       -      +
    368A  LEU*     5.0     2.9    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 230 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    209A  ILE*     3.8    26.7    -      -       +      +
    212A  ILE*     3.7    28.9    -      -       +      -
    213A  CYS*     3.9    14.1    -      -       -      +
    217A  LEU*     5.1     4.9    -      -       +      -
    226A  ASN      3.4    11.1    +      -       -      +
    227A  LEU      3.4     8.6    +      -       -      +
    229A  ARG*     1.3    76.4    -      -       -      +
    231A  ILE*     1.3    65.1    +      -       -      +
    233A  GLN*     3.3     6.3    +      -       +      +
    234A  ILE*     3.2    43.0    +      -       +      +
    272A  TYR*     4.9     1.8    -      -       +      -
    275A  VAL*     4.1    25.8    -      -       +      -
    302A  MET*     6.0     0.4    -      -       +      -
    368A  LEU*     4.3    19.3    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 231 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     16A  ILE*     4.0    31.0    -      -       +      -
    171A  ILE*     4.4    11.9    -      -       +      -
    204A  VAL*     4.1    14.8    -      -       +      -
    206A  ASN*     4.5     1.3    -      -       -      +
    209A  ILE*     4.0    25.1    -      -       +      -
    227A  LEU*     2.8    30.1    +      -       +      +
    228A  ASN*     3.2    14.1    +      -       -      +
    230A  LEU*     1.3    72.9    -      -       -      +
    232A  SER*     1.3    57.8    +      -       -      +
    234A  ILE*     3.2    10.6    +      -       +      +
    235A  VAL*     2.9    33.6    +      -       +      +
    302A  MET*     6.0     0.4    -      -       -      -
    501A  GTP      3.5    28.7    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 232 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     16A  ILE*     4.7     0.4    -      -       -      -
     19A  ALA*     3.3    15.5    +      -       -      +
     20A  CYS*     3.5    46.0    -      -       -      +
     23A  LEU*     3.4     8.6    -      -       -      +
    228A  ASN      2.6    22.8    +      -       -      -
    229A  ARG*     3.0    13.7    +      -       -      -
    231A  ILE*     1.3    72.6    -      -       -      +
    233A  GLN*     1.3    56.4    +      -       -      +
    235A  VAL*     3.8     0.5    -      -       -      +
    236A  SER*     2.8    34.8    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 233 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     23A  LEU*     3.2    29.5    -      -       -      +
     27A  GLU*     5.0     0.8    +      -       -      -
    229A  ARG      3.3    16.4    +      -       -      +
    230A  LEU*     3.5     8.7    -      -       +      +
    231A  ILE      3.3     0.4    -      -       -      -
    232A  SER*     1.3    74.4    -      -       -      +
    234A  ILE*     1.3    67.2    +      -       +      +
    236A  SER*     3.4     2.2    +      -       -      -
    237A  SER*     3.0    24.8    +      -       -      -
    272A  TYR*     3.7    26.7    +      -       +      +
    320A  ARG*     4.9     1.1    +      -       -      +
    360A  PRO*     3.9    13.7    -      -       -      +
    361A  THR      2.8    28.6    +      -       -      +
    362A  VAL*     4.6     6.8    -      -       -      +
    363A  VAL*     5.4     1.6    -      -       -      +
    368A  LEU*     3.6    27.7    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 234 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    169A  PHE*     5.9     0.2    -      -       +      -
    204A  VAL*     5.5     7.6    -      -       +      -
    230A  LEU*     3.2    34.5    -      -       +      +
    231A  ILE*     3.2    10.3    +      -       -      +
    233A  GLN*     1.3    78.2    -      -       -      +
    235A  VAL*     1.3    67.2    +      -       +      +
    237A  SER*     3.2    10.7    -      -       -      -
    238A  ILE*     3.1    39.7    +      -       +      +
    270A  ALA*     4.3    14.8    -      -       +      -
    272A  TYR*     3.7    45.5    -      -       +      -
    275A  VAL*     5.9     0.2    -      -       +      -
    302A  MET*     3.9    28.7    -      -       +      -
    376A  CYS*     4.6     3.4    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 235 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     16A  ILE*     5.0     0.4    -      -       +      -
     20A  CYS*     3.8    24.2    -      -       -      -
     24A  TYR*     3.5    20.0    -      -       -      +
    138A  PHE*     3.9    20.9    -      -       +      -
    169A  PHE*     3.9    26.0    -      -       +      -
    204A  VAL*     6.2     0.9    -      -       +      -
    231A  ILE*     2.9    34.8    +      -       +      +
    232A  SER      3.8     0.4    -      -       -      +
    234A  ILE*     1.3    77.0    -      -       +      +
    236A  SER*     1.3    58.3    +      -       -      +
    238A  ILE*     3.0    10.6    +      -       -      +
    239A  THR*     2.8    34.7    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 236 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     23A  LEU*     3.6    10.5    -      -       -      -
     24A  TYR*     4.0     8.8    -      -       -      -
     27A  GLU*     2.6    17.7    +      -       -      -
    232A  SER      2.8    23.2    +      -       -      -
    233A  GLN*     3.6     4.0    -      -       -      -
    235A  VAL*     1.3    72.9    -      -       -      +
    237A  SER*     1.3    54.3    +      -       -      +
    239A  THR*     3.1     3.8    +      -       -      -
    240A  ALA*     2.7    33.3    +      -       -      +
    243A  ARG*     2.9    22.1    +      -       -      +
    320A  ARG*     2.5    26.3    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 237 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    233A  GLN      3.0    11.4    +      -       -      -
    234A  ILE*     3.2    13.0    -      -       -      -
    236A  SER*     1.3    76.4    -      -       -      +
    238A  ILE*     1.3    61.7    +      -       -      +
    240A  ALA*     3.7    10.6    +      -       -      +
    241A  SER      4.8     1.2    +      -       -      -
    272A  TYR*     3.5    20.8    +      -       -      -
    318A  LEU*     3.7    20.1    +      -       -      +
    320A  ARG*     3.6    26.0    +      -       -      +
    375A  VAL      5.0     0.2    -      -       -      -
    376A  CYS*     3.6    25.5    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 238 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    167A  LEU*     5.8     0.9    -      -       +      -
    169A  PHE*     3.8    28.0    -      -       +      -
    202A  PHE*     3.8    29.4    -      -       +      -
    234A  ILE*     3.1    34.1    +      -       +      +
    235A  VAL      3.0     7.1    +      -       -      +
    237A  SER*     1.3    78.0    -      -       -      +
    239A  THR*     1.3    62.4    +      -       +      +
    240A  ALA      3.7     0.2    +      -       -      -
    241A  SER*     3.8     6.1    +      -       -      -
    255A  PHE*     3.3    38.2    -      -       +      -
    270A  ALA*     4.8     2.2    -      -       +      -
    318A  LEU*     4.3     8.4    -      -       +      +
    376A  CYS*     4.3     5.4    -      -       -      -
    378A  LEU*     3.9    28.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 239 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     24A  TYR*     3.0    27.9    +      -       -      +
     52A  PHE*     4.0    18.6    -      -       +      -
    136A  LEU*     4.8     9.0    -      -       +      -
    138A  PHE*     5.7     0.7    -      -       +      -
    169A  PHE*     4.4    15.9    -      -       +      -
    235A  VAL*     2.8    30.4    +      -       +      +
    238A  ILE*     1.3    72.3    -      -       +      +
    240A  ALA*     1.3    58.5    +      -       -      +
    241A  SER      3.2     2.9    -      -       -      -
    242A  LEU*     2.9    32.9    +      -       +      +
    243A  ARG*     3.1    27.0    +      -       -      -
    255A  PHE*     6.1     0.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 240 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    236A  SER      2.7    19.5    +      -       -      +
    237A  SER      3.8     9.0    -      -       -      +
    238A  ILE      3.4     1.8    -      -       -      -
    239A  THR*     1.3    72.0    -      -       -      +
    241A  SER*     1.3    57.4    +      -       -      +
    243A  ARG*     3.1    17.5    +      -       -      +
    244A  PHE*     2.9    46.9    +      -       +      +
    320A  ARG*     4.2    19.5    -      -       -      +
    356A  ASN*     5.5     5.4    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 241 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    237A  SER      4.8     1.4    +      -       -      -
    238A  ILE      3.8    12.9    +      -       -      -
    240A  ALA*     1.3    78.0    -      -       -      +
    242A  LEU*     1.3    59.0    +      -       -      +
    244A  PHE*     3.4    17.3    -      -       -      +
    246A  GLY*     5.5     2.7    +      -       -      -
    248A  LEU      3.1    25.4    -      -       -      +
    249A  ASN*     2.7    32.5    +      -       -      +
    250A  VAL*     4.0    12.5    -      -       -      +
    255A  PHE*     3.9     2.8    -      -       -      -
    318A  LEU*     5.6     8.9    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 242 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      4A  CYS*     4.5     3.8    -      -       -      -
     48A  SER*     3.3     6.6    +      -       -      +
     51A  THR*     2.8    30.0    +      -       -      +
     52A  PHE*     4.0    26.0    -      -       +      -
    133A  GLN*     4.0    12.6    -      -       -      +
    136A  LEU*     5.0     4.3    -      -       +      -
    239A  THR*     2.9    20.8    +      -       +      +
    241A  SER*     1.3    77.1    +      -       -      +
    243A  ARG*     1.3    54.9    +      -       -      +
    244A  PHE      3.7     0.9    -      -       -      -
    249A  ASN      4.1     1.3    -      -       -      +
    250A  VAL      3.5    24.3    -      -       -      +
    251A  ASP*     3.6    24.7    -      -       -      -
    252A  LEU*     3.8    19.5    -      -       +      +
    255A  PHE*     3.7    27.8    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 243 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     24A  TYR*     3.3    24.2    -      -       -      -
     27A  GLU*     2.7    23.4    +      -       -      +
     28A  HIS*     3.4    46.2    +      -       +      +
     48A  SER*     3.4    13.6    -      -       -      +
     49A  PHE*     3.2    19.8    +      -       -      +
     51A  THR*     4.5     0.4    -      -       -      +
     52A  PHE*     3.7    45.5    -      -       +      -
    236A  SER*     2.9    42.4    +      -       -      +
    239A  THR*     3.1    21.6    +      -       -      +
    240A  ALA*     3.1    15.6    +      -       -      +
    242A  LEU*     1.3    76.3    -      -       -      +
    244A  PHE*     1.3    64.8    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 244 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     27A  GLU*     3.9    30.3    -      -       +      -
     28A  HIS*     3.5    27.1    -      +       -      -
     48A  SER*     3.6    12.1    +      -       -      -
    240A  ALA*     2.9    29.3    +      -       +      +
    241A  SER*     3.4    17.9    -      -       -      +
    242A  LEU      4.7     0.2    -      -       -      -
    243A  ARG*     1.3    89.5    -      -       +      +
    245A  ASP*     1.3    67.2    +      -       -      +
    246A  GLY*     3.5     1.4    +      -       -      -
    250A  VAL*     5.8     0.5    -      -       -      +
    320A  ARG*     4.1    11.4    -      -       -      -
    356A  ASN*     3.7    28.3    -      -       -      +
    358A  GLN*     3.6    23.6    -      -       -      -
     16E  SER*     5.0     5.8    -      -       -      +
----------------------------------------------------------
 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