Contacts of ligand EDO1253A in PDB entry 4ABG

Ligand-Protein Contacts (LPC) are derived with the LPC 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.


On this page you will find:

Table II
Residues in contact with ligand EDO1253A in PDB entry 4ABG
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Legend:
Dist - nearest distance (Å) between atoms of the ligand and the residue
Surf - contact surface area (Å2) between the ligand and the residue
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 contacting ligand by their side chain
       (including CA atoms)

----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue      Dist    Surf    HB    Arom    Phob    DC
----------------------------------------------------------
     96A  SER      5.1     0.4    -      -       -      -
     97A  ASN      3.2    27.9    +      -       -      -
     98A  THR*     3.4    25.3    +      -       -      -
     99A  LEU*     3.9    21.8    -      -       -      -
    175A  GLN*     3.2    23.7    +      -       -      +
    215A  TRP*     3.1    45.0    -      -       -      -
----------------------------------------------------------


Table III
List of putative hydrogen bonds between ligand EDO1253A and protein in PDB entry 4ABG
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Legend:
N     - ligand atom number in PDB entry
Dist  - distance (Å) between the ligand and protein atoms
Surf  - contact surface area (Å2) between the ligand and protein atoms
------------------------------------------------------------------------
    Ligand atom            Protein atom
-----------------   ----------------------------    Dist     Surf
  N   Name   Class    Residue       Name   Class
------------------------------------------------------------------------
  2   O1     I        GLN  175A     NE2    III       3.2     19.9
  2   O1     I        ASN   97A     O      II        3.6      2.6
  2   O1     I        THR   98A     O      II        3.8      0.5
  4   O2     I        THR   98A     O      II        3.6      3.6
------------------------------------------------------------------------


Table IV
Full list of atomic contacts with ligand EDO1253A in PDB entry 4ABG
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Total number of contacts is 27
Legend:
N     - ligand atom number in PDB entry
Dist  - distance (A) between the ligand and protein atoms
Surf  - contact surface area (A**2) between the ligand and protein atoms
*     - indicates destabilizing contacts
------------------------------------------------------------------------
    Ligand atom            Protein atom
-----------------   ----------------------------    Dist     Surf
  N   Name   Class    Residue       Name   Class
------------------------------------------------------------------------
  1   C1     VI      ASN   97A     O      II        3.2      24.9  
  1   C1     VI      THR   98A     C      VI        3.4      16.6  
  1   C1     VI      ASN   97A     C      VI        4.0       0.4  
  1   C1     VI      LEU   99A     N      III       4.0       0.7  
  1   C1     VI      LEU   99A     CG     IV        4.1       1.3  
  1   C1     VI      LEU   99A     CD2    IV        5.1       0.2  
  1   C1     VI      SER   96A     O      II        5.1       0.4  
  2   O1     I       GLN  175A     NE2    III       3.2      19.9  
  2   O1     I       ASN   97A     O      II        3.6       2.6  
  2   O1     I       THR   98A     CA     VII       3.8       4.5  
  2   O1     I       THR   98A     O      II        3.8       0.5  
  2   O1     I       GLN  175A     CG     IV        4.8       1.0* 
  2   O1     I       GLN  175A     CB     IV        5.2       0.7* 
  3   C2     VI      LEU   99A     CG     IV        3.9      15.3  
  3   C2     VI      LEU   99A     CD1    IV        4.1       4.3  
  3   C2     VI      TRP  215A     CD2     V        4.1       4.7  
  3   C2     VI      TRP  215A     CE3     V        4.3       3.1  
  3   C2     VI      TRP  215A     CG      V        4.3       0.4  
  3   C2     VI      GLN  175A     NE2    III       4.5       2.0  
  3   C2     VI      TRP  215A     CB     IV        4.7       1.3  
  4   O2     I       TRP  215A     CD2     V        3.1      25.1  
  4   O2     I       TRP  215A     CE2     V        3.2       6.1  
  4   O2     I       TRP  215A     CE3     V        3.4       1.4  
  4   O2     I       TRP  215A     CG      V        3.5       0.9  
  4   O2     I       THR   98A     O      II        3.6       3.6  
  4   O2     I       TRP  215A     CZ2     V        3.7       1.4  
  4   O2     I       TRP  215A     CZ3     V        3.9       0.5  
------------------------------------------------------------------------


Table V
Complementarity values for the ligand EDO1253A in PDB entry 4ABG
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---------------------------------------------
Theoretical maximum (Å2)                 190
Actual value (Å2)                        140
Normalised complementarity              0.74
---------------------------------------------


Table VI
Normalised complementarity as a function of atomic substitution for ligand EDO1253A in PDB entry 4ABG
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Legend:
N- ligand atom number in PDB entry
Bold - indicates atomic substitution which could stabilize the complex
Italics- indicates atomic substitution which could destabilize the complex
Ligand atomAtom class
NTypeClassI IIIIIIVV VIVIIVIII
1 C1 VI 0.72 0.46 0.72 0.47 0.74 0.74 0.73 0.47
2 O1 I 0.74 0.71 0.48 0.51 0.76 0.76 0.50 0.72
3 C2 VI 0.52 0.52 0.50 0.72 0.74 0.74 0.72 0.74
4 O2 I 0.74 0.70 0.74 0.70 0.74 0.74 0.74 0.70


A short description of the analytical approach (back to top of page)

The analysis of ligand-protein contacts used in this page is based upon the surface complementarity approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129.
The complementarity function therein is defined as:

CF=Sl-Si-E

Where Sl is the sum of all surface areas of legitimate atomic contacts between ligand and receptor, Si is the sum of all surface areas of illegitimate atomic contacts, and E is a repulsion term.

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 ligands are automatically assigned based on the atomic coordinates. However, in three cases the automatic assignment is currently ambiguous (due to low resolution). In these three cases, the user is advised to manually analyze the full list of contacts (Table IV).
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).

IN YOUR STRUCTURE, the following atoms fall in these ambiguous cases:
Ligand EDO 1250
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2 
Ligand EDO 1251
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2 
Ligand EDO 1252
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2 
Ligand EDO 1253
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2 
Ligand EDO 1254
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2 
Ligand 91B 1255
1. Carbon (in rings)
                     1 C11    2 C10    5 C9     4 C8     6 C7     3 C12
                     7 C3     9 C2    10 C6     8 C5 
3. Nitrogen ("hydrophilic")
                    13 N4    14 N1    15 N14


Please E-mail any questions and/or suggestions concerning this page to Vladimir.Sobolev@weizmann.ac.il