Contacts of ligand TPO 780A in PDB entry 4OTD

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 TPO 780A in PDB entry 4OTD
(back to top of page)
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
----------------------------------------------------------
    745A  ARG*     2.7    46.2    +      -       -      -
    769A  LYS*     2.8    28.2    +      -       -      +
    778A  THR*     2.4    31.0    +      -       -      +
    779A  SER*     1.3    70.2    +      -       -      +
    781A  PHE*     1.3    63.2    +      -       -      +
    782A  CYS*     3.2    24.8    +      -       +      -
    792A  VAL*     5.0     0.3    -      -       -      +
    798A  TYR*     2.6    29.6    +      -       -      -
----------------------------------------------------------


Table III
List of putative hydrogen bonds between ligand TPO 780A and protein in PDB entry 4OTD
(back to top of page)
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
------------------------------------------------------------------------
  1   N      I        SER  779A     N      III       2.8      0.6
  1   N      I        TYR  798A     OH     I         4.0      0.4
  7   O1P    I        LYS  769A     NZ     III       2.8     22.0
  7   O1P    I        THR  778A     OG1    I         3.4      1.0
  7   O1P    I        SER  779A     N      III       4.9      0.3
  8   O2P    I        THR  778A     OG1    I         2.4     29.6
  8   O2P    I        ARG  745A     NH1    III       2.7     17.8
  9   O3P    I        ARG  745A     NH2    III       2.8     24.6
  9   O3P    I        ARG  745A     NH1    III       3.3      0.2
 11   O      II       PHE  781A     N      III       2.2      0.5
 11   O      II       TYR  798A     OH     I         2.6     25.5
 11   O      II       CYS  782A     N      III       3.2      5.2
------------------------------------------------------------------------


Table IV
Full list of atomic contacts with ligand TPO 780A in PDB entry 4OTD
(back to top of page)
Total number of contacts is 39
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   N      I       SER  779A     C      VI        1.3      57.2  
  1   N      I       SER  779A     CA     VII       2.5       4.0  
  1   N      I       SER  779A     N      III       2.8       0.6  
  1   N      I       THR  778A     C      VI        4.0       0.2  
  1   N      I       TYR  798A     OH     I         4.0       0.4  
  2   CA     VI      SER  779A     C      VI        2.4       3.8  
  2   CA     VI      PHE  781A     N      III       2.4       3.1  
  2   CA     VI      SER  779A     O      II        2.7       0.7  
  3   CB    VIII     ARG  745A     NH1    III       3.9       3.6  
  4   CG2    IV      PHE  781A     N      III       3.5       2.9* 
  4   CG2    IV      CYS  782A     CB     IV        3.9      18.2  
  4   CG2    IV      CYS  782A     SG     VI        4.1       0.9  
  4   CG2    IV      PHE  781A     C      VI        4.2       1.1  
  4   CG2    IV      PHE  781A     O      II        4.3       1.3* 
  7   O1P    I       LYS  769A     NZ     III       2.8      22.0  
  7   O1P    I       THR  778A     OG1    I         3.4       1.0  
  7   O1P    I       LYS  769A     CE     VII       3.8       0.3  
  7   O1P    I       SER  779A     N      III       4.9       0.3  
  8   O2P    I       THR  778A     OG1    I         2.4      29.6  
  8   O2P    I       ARG  745A     NH1    III       2.7      17.8  
  8   O2P    I       THR  778A     CG2    IV        3.3       0.2* 
  8   O2P    I       LYS  769A     CD     IV        3.8       0.3* 
  9   O3P    I       ARG  745A     NH2    III       2.8      24.6  
  9   O3P    I       ARG  745A     NH1    III       3.3       0.2  
  9   O3P    I       LYS  769A     CD     IV        3.8       5.5* 
 10   C     VIII     PHE  781A     N      III       1.3      44.0  
 10   C     VIII     PHE  781A     CA     VII       2.4       2.5  
 10   C     VIII     SER  779A     O      II        2.9       3.4* 
 10   C     VIII     SER  779A     C      VI        3.0       0.2  
 10   C     VIII     PHE  781A     C      VI        3.1       0.2  
 10   C     VIII     TYR  798A     CE2     V        4.3       0.2  
 11   O      II      PHE  781A     N      III       2.2       0.5  
 11   O      II      TYR  798A     OH     I         2.6      25.5  
 11   O      II      PHE  781A     CA     VII       2.7       7.4  
 11   O      II      CYS  782A     N      III       3.2       5.2  
 11   O      II      TYR  798A     CZ      V        3.4       2.8  
 11   O      II      TYR  798A     CE2     V        3.5       0.7  
 11   O      II      CYS  782A     SG     VI        3.8       0.5  
 11   O      II      VAL  792A     CG1    IV        5.0       0.3* 
------------------------------------------------------------------------


Table V
Complementarity values for the ligand TPO 780A in PDB entry 4OTD
(back to top of page)

---------------------------------------------
Theoretical maximum (Å2)                 323
Actual value (Å2)                        265
Normalised complementarity              0.82
---------------------------------------------


Table VI
Normalised complementarity as a function of atomic substitution for ligand TPO 780A in PDB entry 4OTD
(back to top of page)

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 N I 0.82 0.82 0.79 0.81 0.82 0.82 0.79 0.82
2 CA VI 0.82 0.82 0.80 0.80 0.82 0.82 0.80 0.82
3 CB VIII 0.82 0.82 0.80 0.80 0.82 0.82 0.80 0.82
4 CG2 IV 0.73 0.73 0.72 0.82 0.85 0.85 0.83 0.84
7 O1P I 0.82 0.82 0.68 0.68 0.82 0.82 0.68 0.82
8 O2P I 0.82 0.82 0.71 0.53 0.82 0.82 0.71 0.82
9 O3P I 0.82 0.82 0.67 0.70 0.85 0.85 0.70 0.85
10 C VIII 0.84 0.82 0.55 0.55 0.84 0.84 0.55 0.82
11 O II 0.82 0.82 0.74 0.63 0.82 0.82 0.74 0.82


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 TPO  780
2. Oxygen ("hydroxy" or "carbonyl")
                    11 O  
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand SEP  922
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O  
3. Nitrogen ("hydrophilic")
                     1 N  


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