IUBMB Enzyme Nomenclature


Accepted name: succinylornithine transaminase

Reaction: N2-succinyl-L-ornithine + 2-oxoglutarate = N-succinyl-L-glutamate 5-semialdehyde + L-glutamate

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Other name(s): succinylornithine aminotransferase; N2-succinylornithine 5-aminotransferase; AstC; SOAT

Systematic name: N2-succinyl-L-ornithine:2-oxoglutarate 5-aminotransferase

Comments: A pyridoxal-phosphate protein. Also acts on N2-acetyl-L-ornithine and L-ornithine, but more slowly [3]. In Pseudomonas aeruginosa, the arginine-inducible succinylornithine transaminase, acetylornithine transaminase (EC and ornithine aminotransferase (EC activities are catalysed by the same enzyme, but this is not the case in all species [5]. This is the third enzyme in the arginine succinyltransferase (AST) pathway for the catabolism of arginine [1]. This pathway converts the carbon skeleton of arginine into glutamate, with the concomitant production of ammonia and conversion of succinyl-CoA into succinate and CoA. The five enzymes involved in this pathway are EC (arginine N-succinyltransferase), EC (N-succinylarginine dihydrolase), EC (succinylornithine transaminase), EC (succinylglutamate-semialdehyde dehydrogenase) and EC (succinylglutamate desuccinylase) [3, 6]. Of the five enzymes involved in arginine catabolism, this is the only one that is also involved in ornithine catabolism [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:


1. Vander Wauven, C. and Stalon, V. Occurrence of succinyl derivatives in the catabolism of arginine in Pseudomonas cepacia. J. Bacteriol. 164 (1985) 882-886. [PMID: 2865249]

2. Schneider, B.L., Kiupakis, A.K. and Reitzer, L.J. Arginine catabolism and the arginine succinyltransferase pathway in Escherichia coli. J. Bacteriol. 180 (1998) 4278-4286. [PMID: 9696779]

3. Cunin, R., Glansdorff, N., Pierard, A. and Stalon, V. Biosynthesis and metabolism of arginine in bacteria. Microbiol. Rev. 50 (1986) 314-352. [PMID: 3534538]

4. Itoh, Y. Cloning and characterization of the aru genes encoding enzymes of the catabolic arginine succinyltransferase pathway in Pseudomonas aeruginosa. J. Bacteriol. 179 (1997) 7280-7290. [PMID: 9393691]

5. Stalon, V., Vander Wauven, C., Momin, P. and Legrain, C. Catabolism of arginine, citrulline and ornithine by Pseudomonas and related bacteria. J. Gen. Microbiol. 133 (1987) 2487-2495. [PMID: 3129535]

[EC created 2006]

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