4ADB

Structural and functional study of succinyl-ornithine transaminase from E. coli

Summary for 4ADB

• Entry DOI: 10.2210/pdb4adb/pdb
• Related: 4ADC 4ADD 4ADE
• Descriptor: SUCCINYLORNITHINE TRANSAMINASE, PYRIDOXAL-5'-PHOSPHATE, SODIUM ION, ... (5 entities in total)
• Functional Keywords: transferase, plp enzymes, aminotransferase
• Biological source: ESCHERICHIA COLI
• Total number of polymer chains: 4
• Total formula weight: 175977.97

Authors

Newman, J.,Peat, T.S. (deposition date: 2011-12-23, release date: 2013-01-16, Last modification date: 2023-12-20)

Primary citation

Newman, J.,Seabrook, S.,Surjadi, R.,Williams, C.C.,Lucent, D.,Wilding, M.,Scott, C.,Peat, T.S.
Determination of the Structure of the Catabolic N-Succinylornithine Transaminase (Astc) from Escherichia Coli.
Plos One, 8:58298-, 2013

PubMed 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.

PubMed: 23484010
DOI: 10.1371/JOURNAL.PONE.0058298

Experimental method

X-RAY DIFFRACTION (2.2 Å)