3UNQ | pdb_00003unq

Bovine trypsin variant X(triplePhe227) in complex with small molecule inhibitor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.62 Å
  • R-Value Free: 
    0.196 (Depositor), 0.174 (DCC) 
  • R-Value Work: 
    0.173 (Depositor), 0.174 (DCC) 
  • R-Value Observed: 
    0.175 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 3UNQ

This is version 1.4 of the entry. See complete history

Literature

Correlating structure and ligand affinity in drug discovery: a cautionary tale involving second shell residues.

Tziridis, A.Rauh, D.Neumann, P.Kolenko, P.Menzel, A.Brauer, U.Ursel, C.Steinmetzer, P.Sturzebecher, J.Schweinitz, A.Steinmetzer, T.Stubbs, M.T.

(2014) Biol Chem 395: 891-903

  • DOI: https://doi.org/10.1515/hsz-2014-0158
  • Primary Citation Related Structures: 
    3PLB, 3PLK, 3PLP, 3PM3, 3PMJ, 3PWB, 3PWC, 3PYH, 3Q00, 3UNQ, 3UNS, 3UOP, 3UPE, 3UQO, 3UQV, 3UUZ, 3UWI, 3UY9, 3V12, 3V13

  • PubMed Abstract: 

    A high-resolution crystallographic structure determination of a protein-ligand complex is generally accepted as the 'gold standard' for structure-based drug design, yet the relationship between structure and affinity is neither obvious nor straightforward. Here we analyze the interactions of a series of serine proteinase inhibitors with trypsin variants onto which the ligand-binding site of factor Xa has been grafted. Despite conservative mutations of only two residues not immediately in contact with ligands (second shell residues), significant differences in the affinity profiles of the variants are observed. Structural analyses demonstrate that these are due to multiple effects, including differences in the structure of the binding site, differences in target flexibility and differences in inhibitor binding modes. The data presented here highlight the myriad competing microscopic processes that contribute to protein-ligand interactions and emphasize the difficulties in predicting affinity from structure.

Macromolecule Content 

  • Total Structure Weight: 24.22 kDa 
  • Atom Count: 2,020 
  • Modeled Residue Count: 223 
  • Deposited Residue Count: 223 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Cationic trypsin223Bos taurusMutation(s): 9 
EC: 3.4.21.4
UniProt
Find proteins for P00760 (Bos taurus)
Explore P00760 
Go to UniProtKB:  P00760
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00760
Sequence Annotations
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Reference Sequence

Small Molecules

Ligands 6 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
BEN

Query on BEN



Download:Ideal Coordinates CCD File
C [auth A]BENZAMIDINE
C7 H8 N2
PXXJHWLDUBFPOL-UHFFFAOYSA-N
PEG

Query on PEG



Download:Ideal Coordinates CCD File
I [auth A]DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
SO4

Query on SO4



Download:Ideal Coordinates CCD File
D [auth A],
J [auth A]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
GOL

Query on GOL



Download:Ideal Coordinates CCD File
E [auth A],
F [auth A],
G [auth A]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
EDO

Query on EDO



Download:Ideal Coordinates CCD File
H [auth A]1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
CA

Query on CA



Download:Ideal Coordinates CCD File
B [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.62 Å
  • R-Value Free:  0.196 (Depositor), 0.174 (DCC) 
  • R-Value Work:  0.173 (Depositor), 0.174 (DCC) 
  • R-Value Observed: 0.175 (Depositor) 
Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.836α = 90
b = 64.088β = 90
c = 70.518γ = 90
Software Package:
Software NamePurpose
MxCuBEdata collection
MOLREPphasing
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-11-21
    Type: Initial release
  • Version 1.1: 2014-07-16
    Changes: Database references
  • Version 1.2: 2018-12-05
    Changes: Data collection, Source and taxonomy
  • Version 1.3: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.4: 2024-10-30
    Changes: Structure summary