Contacts of the helix formed by residues 20 - 25 (chain K) in PDB entry 4QOC


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 PRO 20 (chain K).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     18K  GLN      3.6     8.3    -      -       -      +
     19K  ILE*     1.3    94.7    -      -       +      +
     21K  ALA*     1.3    63.5    +      -       -      +
     22K  SER*     3.0    24.0    +      -       -      +
     23K  GLU*     3.2    24.3    +      -       +      +
     24K  GLN*     4.7     0.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 21 (chain K). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     21C  ALA*     5.8     2.2    -      -       +      +
     24C  GLN*     4.8     7.9    -      -       -      +
     25C  GLU*     4.0     9.2    -      -       +      +
     51C  LYS*     3.8    26.5    -      -       -      +
     19K  ILE      3.9     1.4    +      -       -      -
     20K  PRO*     1.3    72.1    -      -       -      +
     22K  SER*     1.3    61.8    +      -       -      +
     23K  GLU      3.2     1.2    +      -       -      -
     24K  GLN*     3.4    18.9    +      -       -      +
     25K  GLU*     3.5    10.0    -      -       -      +
----------------------------------------------------------
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Residues in contact with SER 22 (chain K). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     25C  GLU*     3.6    31.7    +      -       -      +
     20K  PRO*     3.0    16.7    -      -       -      +
     21K  ALA*     1.3    79.5    -      -       -      +
     23K  GLU*     1.3    66.3    +      -       -      +
     25K  GLU*     2.9    23.5    +      -       -      +
     26K  THR*     3.6     4.9    +      -       -      -
----------------------------------------------------------
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Residues in contact with GLU 23 (chain K). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     19K  ILE*     4.3     9.6    -      -       +      -
     20K  PRO*     3.2    20.9    +      -       +      +
     22K  SER*     1.3    84.0    +      -       -      +
     24K  GLN*     1.3    59.9    +      -       +      +
     26K  THR*     2.8    33.9    +      -       -      +
     50K  MET*     3.3    12.0    -      -       -      +
    100K  TYR*     3.6    42.9    -      -       +      +
    104K  TYR*     2.5    38.8    +      -       -      -
----------------------------------------------------------
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Residues in contact with GLN 24 (chain K). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     21K  ALA*     3.4    12.9    +      -       -      +
     22K  SER      3.1     1.8    +      -       -      -
     23K  GLU*     1.3    76.1    -      -       +      +
     25K  GLU*     1.3    59.6    +      -       +      +
     26K  THR      3.4     0.4    -      -       -      -
     49K  THR*     4.0     2.9    -      -       -      -
     50K  MET*     3.6     9.6    +      -       -      -
     51K  LYS*     2.9    61.3    +      -       +      +
     54K  LEU*     3.9    14.3    -      -       +      +
    100K  TYR*     3.6    18.7    +      -       -      +
    201K  35T      3.9    21.1    -      -       -      -
----------------------------------------------------------
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Residues in contact with GLU 25 (chain K). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     21C  ALA*     3.7    16.1    -      -       +      +
     22C  SER*     3.0    39.4    +      -       -      +
     25C  GLU*     2.4    34.1    -      -       -      +
     45E  LYS*     3.7    22.2    +      -       +      +
     52E  GLU*     5.3     1.3    -      -       -      +
     21K  ALA*     3.5    11.4    -      -       -      +
     22K  SER*     2.9    11.5    +      -       -      +
     24K  GLN*     1.3    79.8    -      -       +      +
     26K  THR*     1.3    65.7    +      -       -      +
     27K  LEU*     3.4    16.3    +      -       -      +
     49K  THR*     4.7     6.6    -      -       -      +
     50K  MET      4.7     0.2    -      -       -      -
----------------------------------------------------------
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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