1VZ8

Ornithine Acetyltransferase (ORF6 Gene Product - Clavulanic Acid Biosynthesis) from Streptomyces clavuligerus (SeMet structure)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.288 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.235 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

X-Ray Crystal Structure of Ornithine Acetyltransferase from the Clavulanic Acid Biosynthesis Gene Cluster.

Elkins, J.M.Kershaw, N.J.Schofield, C.J.

(2005) Biochem J 385: 565

  • DOI: https://doi.org/10.1042/BJ20040814
  • Primary Citation of Related Structures:  
    1VZ6, 1VZ7, 1VZ8

  • PubMed Abstract: 

    The orf6 gene from the clavulanic acid biosynthesis gene cluster encodes an OAT (ornithine acetyltransferase). Similar to other OATs the enzyme has been shown to catalyse the reversible transfer of an acetyl group from N-acetylornithine to glutamate. OATs are Ntn (N-terminal nucleophile) enzymes, but are distinct from the better-characterized Ntn hydrolase enzymes as they catalyse acetyl transfer rather than a hydrolysis reaction. In the present study, we describe the X-ray crystal structure of the OAT, corresponding to the orf6 gene product, to 2.8 A (1 A=0.1 nm) resolution. The larger domain of the structure consists of an alphabetabetaalpha sandwich as in the structures of Ntn hydrolase enzymes. However, differences in the connectivity reveal that OATs belong to a structural family different from that of other structurally characterized Ntn enzymes, with one exception: unexpectedly, the alphabetabetaalpha sandwich of ORF6 (where ORF stands for open reading frame) displays the same fold as an DmpA (L-aminopeptidase D-ala-esterase/amidase from Ochrobactrum anthropi), and so the OATs and DmpA form a new structural subfamily of Ntn enzymes. The structure reveals an alpha2beta2-heterotetrameric oligomerization state in which the intermolecular interface partly defines the active site. Models of the enzyme-substrate complexes suggest a probable oxyanion stabilization mechanism as well as providing insight into how the enzyme binds its two differently charged substrates.


  • Organizational Affiliation

    Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ORNITHINE ACETYL-TRANSFERASE
A, B, C, D
393Streptomyces clavuligerusMutation(s): 0 
EC: 2.3.1.35
UniProt
Find proteins for P0DJQ5 (Streptomyces clavuligerus)
Explore P0DJQ5 
Go to UniProtKB:  P0DJQ5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DJQ5
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.75 Å
  • R-Value Free: 0.288 
  • R-Value Work: 0.235 
  • R-Value Observed: 0.235 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.792α = 90
b = 180.194β = 90.08
c = 73.326γ = 90
Software Package:
Software NamePurpose
CNSrefinement
MOSFLMdata reduction
SCALAdata scaling
SHARPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-09-16
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance