Contacts of the helix formed by residues 25 - 28 (chain S) in PDB entry 1XU2


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 GLN 25 (chain S).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    196D  ASP*     5.5     2.1    -      -       -      +
     23S  PRO*     3.1    13.5    -      -       +      +
     24S  CYS*     1.3    77.9    -      -       -      +
     26S  LEU*     1.3    87.6    +      -       -      +
     27S  ARG      3.3     0.9    +      -       -      -
     28S  CYS*     3.4    18.7    +      -       -      +
     29S  SER*     4.7     1.4    +      -       -      -
     40S  TYR*     3.9    26.1    -      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 26 (chain S). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    167B  PHE*     3.9    38.1    +      -       +      +
    194D  ASP*     5.3     1.3    -      -       -      +
    196D  ASP*     3.5    40.2    -      -       +      +
    197D  ARG*     4.0    33.9    +      -       +      +
     22S  ILE*     3.9    14.1    -      -       +      -
     23S  PRO*     3.2    21.6    +      -       +      +
     24S  CYS      3.1     0.6    -      -       -      -
     25S  GLN*     1.3   100.9    -      -       -      +
     27S  ARG*     1.3    59.3    +      -       -      +
     28S  CYS      3.5     0.4    -      -       -      -
     29S  SER*     4.0    12.6    +      -       -      -
     30S  SER*     5.1     0.7    +      -       -      -
----------------------------------------------------------
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Residues in contact with ARG 27 (chain S). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    123B  ASP*     5.5     2.8    +      -       -      +
    166B  THR*     3.5    26.1    -      -       -      +
    167B  PHE*     3.8    13.0    -      -       +      -
    221B  PRO      4.8     2.0    +      -       -      -
    222B  ARG*     3.7    45.8    -      -       -      +
    223B  ALA      5.0     0.4    -      -       -      +
     13S  TYR*     3.0    60.7    +      -       +      +
     24S  CYS*     3.0    11.3    +      -       -      +
     26S  LEU*     1.3    78.0    -      -       -      +
     28S  CYS*     1.3    60.4    +      -       -      +
     29S  SER      3.4     2.5    -      -       -      -
     30S  SER*     3.0    29.5    +      -       -      -
     32S  THR      3.6    21.4    +      -       -      -
     33S  PRO*     3.9    10.9    -      -       +      +
     34S  PRO*     3.6    30.9    -      -       +      +
     37S  CYS*     5.2     0.4    -      -       +      -
     41S  CYS*     4.4     1.6    -      -       -      -
----------------------------------------------------------
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Residues in contact with CYS 28 (chain S). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     24S  CYS      3.5    10.1    -      -       -      -
     25S  GLN*     3.4    18.1    +      -       -      +
     27S  ARG*     1.3    75.9    -      -       -      +
     29S  SER*     1.3    63.7    +      -       -      +
     30S  SER      3.6     5.9    +      -       -      +
     33S  PRO*     5.0     2.7    -      -       -      +
     40S  TYR*     4.2     8.5    -      -       -      -
     41S  CYS*     2.1    56.9    -      -       +      +
----------------------------------------------------------
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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