3CLA

REFINED CRYSTAL STRUCTURE OF TYPE III CHLORAMPHENICOL ACETYLTRANSFERASE AT 1.75 ANGSTROMS RESOLUTION


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Work: 0.157 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Refined crystal structure of type III chloramphenicol acetyltransferase at 1.75 A resolution.

Leslie, A.G.

(1990) J Mol Biol 213: 167-186

  • DOI: https://doi.org/10.1016/S0022-2836(05)80129-9
  • Primary Citation of Related Structures:  
    3CLA

  • PubMed Abstract: 

    High level bacterial resistance to chloramphenicol is generally due to O-acetylation of the antibiotic in a reaction catalysed by chloramphenicol acetyltransferase (CAT, EC 2.3.1.28) in which acetyl-coenzyme A is the acyl donor. The crystal structure of the type III enzyme from Escherichia coli with chloramphenicol bound has been determined and refined at 1.75 A resolution, using a restrained parameter reciprocal space least squares procedure. The refined model, which includes chloramphenicol, 204 solvent molecules and two cobalt ions has a crystallographic R-factor of 18.3% for 27,300 reflections between 6 and 1.75 A resolution. The root-mean-square deviation in bond lengths from ideal values is 0.02 A. The cobalt ions play a crucial role in stabilizing the packing of the molecule in the crystal lattice. CAT is a trimer of identical subunits (monomer Mr 25,000) and the trimeric structure is stabilized by a number of hydrogen bonds, some of which result in the extension of a beta-sheet across the subunit interface. Chloramphenicol binds in a deep pocket located at the boundary between adjacent subunits of the trimer, such that the majority of residues forming the binding pocket belong to one subunit while the catalytically essential histidine belongs to the adjacent subunit. His195 is appropriately positioned to act as a general base catalyst in the reaction, and the required tautomeric stabilization is provided by an unusual interaction with a main-chain carbonyl oxygen.


  • Organizational Affiliation

    Blackett Laboratory, Imperial College, London, U.K.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TYPE III CHLORAMPHENICOL ACETYLTRANSFERASE213Escherichia coliMutation(s): 0 
EC: 2.3.1.28
UniProt
Find proteins for P00484 (Escherichia coli)
Explore P00484 
Go to UniProtKB:  P00484
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00484
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CLM
Query on CLM

Download Ideal Coordinates CCD File 
D [auth A]CHLORAMPHENICOL
C11 H12 Cl2 N2 O5
WIIZWVCIJKGZOK-RKDXNWHRSA-N
CO
Query on CO

Download Ideal Coordinates CCD File 
B [auth A],
C [auth A]
COBALT (II) ION
Co
XLJKHNWPARRRJB-UHFFFAOYSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
CLM Binding MOAD:  3CLA Kd: 1.30e+4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Work: 0.157 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 107.6α = 90
b = 107.6β = 90
c = 123.6γ = 120
Software Package:
Software NamePurpose
DERIVrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1990-10-15
    Type: Initial release
  • Version 1.1: 2008-03-25
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 2.0: 2024-02-21
    Changes: Atomic model, Data collection, Database references, Derived calculations, Other