PDBsum entry 4ade

Transferase

PDB id: 4ade

Contents

Protein chains

400 a.a.

350 a.a.

Waters ×60

PDB id:

4ade

Name:

Transferase

Title:

Structural and functional study of succinyl-ornithine transaminase from e. Coli

Structure:

Succinylornithine transaminase. Chain: a, b. Synonym: soat, carbon starvation protein c, succinylornithine aminotransferase. Ec: 2.6.1.17, 2.6.1.81

Source:

Escherichia coli. Organism_taxid: 511693. Strain: bl21

Resolution:

2.75Å R-factor: 0.156 R-free: 0.201

Authors:

J.Newman,T.S.Peat

Key ref:

J.Newman et al. (2013). Determination of the structure of the catabolic N-succinylornithine transaminase (AstC) from Escherichia coli. Plos One, 8, e58298. PubMed id: 23484010 DOI: 10.1371/journal.pone.0058298

Date:

23-Dec-11 Release date: 16-Jan-13

Protein chain

P77581  (ASTC_ECOLI) -  Succinylornithine transaminase from Escherichia coli (strain K12)

Seq: 406 a.a.

Struc: 400 a.a.

Protein chain

P77581  (ASTC_ECOLI) -  Succinylornithine transaminase from Escherichia coli (strain K12)

Seq: 406 a.a.

Struc: 350 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.2.6.1.81 - succinylornithine transaminase.
• Reaction: N₂-succinyl-L-ornithine + 2-oxoglutarate = N-succinyl-L-glutamate 5-semialdehyde + L-glutamate
• Cofactor: Pyridoxal 5'-phosphate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1371/journal.pone.0058298

Plos One 8:e58298 (2013)

PubMed id: 23484010

Determination of the structure of the catabolic N-succinylornithine transaminase (AstC) from Escherichia coli.

J.Newman, S.Seabrook, R.Surjadi, C.C.Williams, D.Lucent, M.Wilding, C.Scott, T.S.Peat.

ABSTRACT

Escherichia coli possesses two acyl ornithine aminotransferases, one catabolic (AstC) and the other anabolic (ArgD), that participate in L-arginine metabolism. Although only 58% identical, the enzymes have been shown to be functionally interchangeable. Here we have purified AstC and have obtained X-ray crystal structures of apo and holo-AstC and of the enzyme complexed with its physiological substrate, succinylornithine. We compare the structures obtained in this study with those of ArgD from Salmonella typhimurium obtained elsewhere, finding several notable differences. Docking studies were used to explore the docking modes of several substrates (ornithine, succinylornithine and acetylornithine) and the co-substrate glutamate/α-ketogluterate. The docking studies support our observations that AstC has a strong preference for acylated ornithine species over ornithine itself, and suggest that the increase in specificity associated with acylation is caused by steric and desolvation effects rather than specific interactions between the substrate and enzyme.