1M6K

Structure of the OXA-1 class D beta-lactamase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.182 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Comparison of beta-lactamases of classes A and D: 1.5A crystallographic structure of the class D OXA-1 oxacillinase

Sun, T.Nukaga, M.Mayama, K.Braswell, E.H.Knox, J.R.

(2003) Protein Sci 12: 82-91

  • DOI: 10.1110/ps.0224303
  • Primary Citation of Related Structures:  
    1M6K

  • PubMed Abstract: 
  • The crystallographic structure of the Escherichia coli OXA-1 beta-lactamase has been established at 1.5-A resolution and refined to R = 0.18. The 28.2-kD oxacillinase is a class D serine beta-lactamase that is especially active against the penicillin-type beta-lactams oxacillin and cloxacillin ...

    The crystallographic structure of the Escherichia coli OXA-1 beta-lactamase has been established at 1.5-A resolution and refined to R = 0.18. The 28.2-kD oxacillinase is a class D serine beta-lactamase that is especially active against the penicillin-type beta-lactams oxacillin and cloxacillin. In contrast to the structures of OXA-2, OXA-10, and OXA-13 belonging to other subclasses, the OXA-1 molecule is monomeric rather than dimeric and represents the subclass characterized by an enlarged Omega loop near the beta-lactam binding site. The 6-residue hydrophilic insertion in this loop cannot interact directly with substrates and, instead, projects into solvent. In this structure at pH 7.5, carboxylation of the conserved Lys 70 in the catalytic site is observed. One oxygen atom of the carboxylate group is hydrogen bonded to Ser 120 and Trp 160. The other oxygen atom is more exposed and hydrogen bonded to the Ogamma of the reactive Ser 67. In the overlay of the class D and class A binding sites, the carboxylate group is displaced ca. 2.6 A from the carboxylate group of Glu 166 of class A enzymes. However, each group is equidistant from the site of the water molecule expected to function in hydrolysis, and which could be activated by the carboxylate group of Lys 70. In this ligand-free OXA-1 structure, no water molecule is seen in this site, so the water molecule must enter after formation of the acyl-Ser 67 intermediate.


    Related Citations: 
    • Crystallization and preliminary X-ray study of OXA-1, a class D beta-lactamase
      Sun, T., Nukaga, M., Mayama, K., Crichlow, G.V., Kuzin, A.P., Knox, J.R.
      (2001) Acta Crystallogr D Biol Crystallogr 57: 1912

    Organizational Affiliation

    Department of Molecular and Cell Biology, The University of Connecticut, Storrs, CT 06269, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
beta-lactamase OXA-1A, B251Escherichia coliMutation(s): 0 
Gene Names: oxa1bla
EC: 3.5.2.6
UniProt
Find proteins for P13661 (Escherichia coli)
Explore P13661 
Go to UniProtKB:  P13661
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
KCX
Query on KCX
A, BL-PEPTIDE LINKINGC7 H14 N2 O4LYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.203 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.182 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 36.02α = 70.19
b = 51.62β = 84.11
c = 72.89γ = 81.51
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
EPMRphasing
CNSrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-01-14
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance