N2-Succinylated intermediates in an arginine catabolic pathway of Pseudomonas aeruginosa
AUTOR(ES)
Jann, Alfred
RESUMO
Arginine-nonutilizing (aru) mutants of Pseudomonas aeruginosa strain PAO converted L-arginine to N2-succinylarginine or N-succinylglutamate, which were identified by high-voltage electrophoresis and HPLC. Addition of aminooxyacetate, an inhibitor of pyridoxal phosphate-dependent enzymes, to resting cells of the wild-type PAO1 in arginine medium led to the accumulation of N2-succinylornithine. Enzyme assays with crude P. aeruginosa extracts established the following pathway: L-arginine + succinyl-CoA → N2-succinylarginine → N2-succinylornithine → N_succinylglutamate 5-semialdehyde → N-succinylglutamate → succinate + glutamate. Succinyl-CoA may be regenerated from glutamate via 2-ketoglutarate. L-Arginine induced the enzymes of the pathway, and succinate caused catabolite repression. Purified N2-acetylornithine 5-aminotransferase (N2-acetyl-L-ornithine: 2-oxoglutarate aminotransferase, EC 2.6.1.11), an arginine biosynthetic enzyme, efficiently transaminated N2-succinylornithine; this explains the enzyme's dual role in arginine biosynthesis and catabolism. The succinylarginine pathway enables P. aeruginosa to utilize arginine efficiently as a carbon source under aerobic conditions, whereas the other three arginine catabolic pathways previously established in P. aeruginosa fulfill different functions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=323859Documentos Relacionados
- Cloning and characterization of the aru genes encoding enzymes of the catabolic arginine succinyltransferase pathway in Pseudomonas aeruginosa.
- Dual role for N-2-acetylornithine 5-aminotransferase from Pseudomonas aeruginosa in arginine biosynthesis and arginine catabolism.
- Regulation of enzyme synthesis in the arginine deiminase pathway of Pseudomonas aeruginosa.
- An Analysis of Arginine Requiring Mutants in PSEUDOMONAS AERUGINOSA
- Pseudomonas aeruginosa mutants affected in anaerobic growth on arginine: evidence for a four-gene cluster encoding the arginine deiminase pathway.
