Pseudomonas cepacia NCTC 10743利用精氨酸作为唯一的碳和氮源进行生长。精氨酸通过琥珀酰衍生物降解为谷氨酸。该途径中的分解序列为L-精氨酸----N2-琥珀酰精氨酸----N2-琥珀酰鸟氨酸----N2-琥珀酰谷氨酰半胱氨酸----N2-琥珀酰谷氨酸----谷氨酸+琥珀酸。负责精氨酸降解的酶的形成不仅受到诱导的调控,还受到碳和氮代谢抑制的调控。
The arginine succinyltransferase (AST) pathway is the major arginine and ornithine utilization (aru) pathway under aerobic conditions in Pseudomonas aeruginosa. A 26-kb DNA fragment of the P. aeruginosa PAO1 chromosome carrying the regulatory argR gene and the aru structural gene cluster was cloned. Complementation tests and nucleotide sequence data established the locations of the argR, aruC, aruF, aruG, aruD, aruB, and aruE genes, in that order. The aruR, aruC, aruD, aruB, and aruE genes specify the ArgR regulatory protein, N2-succinylornithine 5-aminotransferase, N-succinylglutamate 5-semialdehyde dehydrogenase, N2-succinylarginine dihydrolase, and N-succinylglutamate desuccinylase, respectively, and the aruF and aruG genes encode the subunits (AruAI and AruAII) of arginine and ornithine N2-succinyltransferases. Furthermore, in vivo analysis of transcriptional aru fusions and of polar insertion mutations located at different sites in the aru cluster indicated the presence of three transcriptional units which are controlled by ArgR. The aruCFGDB genes appear to form an operon transcribed from a promoter upstream of aruC, whereas aruE has its own promoter. The argR gene, which is located upstream of the aruCFGDB operon, is a member of another (aot) operon coding for arginine transport genes. The deduced amino acid sequences of the AST enzymes were compared to those of homologous proteins of Escherichia coli specified by the ast genes lying in the chromosome region from 39.2 to 39.5 min (Kohara clone 327; GenBank/EMBL/DDJB accession no. D90818). The overall organization of the aru and ast genes in both organisms is similar, with the exception that E. coli appears to have a single AST gene.