Publications

• N2-succinylornithine in ornithine catabolism of Pseudomonas aeruginosa.

  Vander Wauven C., Jann A., Haas D., Leisinger T., Stalon V.

  Most Pseudomonas aeruginosa PAO mutants which were unable to utilize L-arginine as the sole carbon and nitrogen source (aru mutants) under aerobic conditions were also affected in L-ornithine utilization. These aru mutants were impaired in one or several enzymes involved in the conversion of N2-su ... >> More

  Most Pseudomonas aeruginosa PAO mutants which were unable to utilize L-arginine as the sole carbon and nitrogen source (aru mutants) under aerobic conditions were also affected in L-ornithine utilization. These aru mutants were impaired in one or several enzymes involved in the conversion of N2-succinylornithine to glutamate and succinate, indicating that the latter steps of the arginine succinyltransferase pathway can be used for ornithine catabolism. Addition of aminooxyacetate, an inhibitor of the N2-succinylornithine 5-aminotransferase, to resting cells of P. aeruginosa in ornithine medium led to the accumulation of N2-succinylornithine. In crude extracts of P. aeruginosa an ornithine succinyltransferase (L-ornithine:succinyl-CoA N2-succinyltransferase) activity could be detected. An aru mutant having reduced arginine succinyltransferase activity also had correspondingly low levels of ornithine succinyltransferase. Thus, in P. aeruginosa, these two activities might be due to the same enzyme, which initiates aerobic arginine and ornithine catabolism. << Less

  Arch Microbiol 150:400-404(1988) [PubMed] [EuropePMC]

• Enzyme genomics: application of general enzymatic screens to discover new enzymes.

  Kuznetsova E., Proudfoot M., Sanders S.A., Reinking J., Savchenko A., Arrowsmith C.H., Edwards A.M., Yakunin A.F.

  In all sequenced genomes, a large fraction of predicted genes encodes proteins of unknown biochemical function and up to 15% of the genes with "known" function are mis-annotated. Several global approaches are routinely employed to predict function, including sophisticated sequence analysis, gene e ... >> More

  In all sequenced genomes, a large fraction of predicted genes encodes proteins of unknown biochemical function and up to 15% of the genes with "known" function are mis-annotated. Several global approaches are routinely employed to predict function, including sophisticated sequence analysis, gene expression, protein interaction, and protein structure. In the first coupling of genomics and enzymology, Phizicky and colleagues undertook a screen for specific enzymes using large pools of partially purified proteins and specific enzymatic assays. Here we present an overview of the further developments of this approach, which involve the use of general enzymatic assays to screen individually purified proteins for enzymatic activity. The assays have relaxed substrate specificity and are designed to identify the subclass or sub-subclasses of enzymes (phosphatase, phosphodiesterase/nuclease, protease, esterase, dehydrogenase, and oxidase) to which the unknown protein belongs. Further biochemical characterization of proteins can be facilitated by the application of secondary screens with natural substrates (substrate profiling). We demonstrate here the feasibility and merits of this approach for hydrolases and oxidoreductases, two very broad and important classes of enzymes. Application of general enzymatic screens and substrate profiling can greatly speed up the identification of biochemical function of unknown proteins and the experimental verification of functional predictions produced by other functional genomics approaches. << Less

  FEMS Microbiol. Rev. 29:263-279(2005) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Purification and properties of a succinyltransferase from Pseudomonas aeruginosa specific for both arginine and ornithine.

  Tricot C., Vander Wauven C., Wattiez R., Falmagne P., Stalon V.

  The arginine and ornithine succinyltransferase from Pseudomonas aeruginosa, a bifunctional enzyme involved in the aerobic utilization of arginine and ornithine, has been purified to homogeneity. The apparent molecular mass of the native enzyme was 150 kDa by gel filtration and 140 kDa by polyacryl ... >> More

  The arginine and ornithine succinyltransferase from Pseudomonas aeruginosa, a bifunctional enzyme involved in the aerobic utilization of arginine and ornithine, has been purified to homogeneity. The apparent molecular mass of the native enzyme was 150 kDa by gel filtration and 140 kDa by polyacrylamide gel electrophoresis under non-denaturing conditions. After SDS/PAGE two subunits of 35 kDa and 37 kDa were evident, indicating that the enzyme is a heterotetramer. Microsequence analysis of the electroblotted protein bands gave two different but well-conserved N-terminal amino acid sequences. The L-arginine saturation curve followed Henri-Michaelis kinetics with an apparent Km value of 0.5 mM. The sigmoidal saturation curve for L-ornithine indicated allosteric behaviour. D-Arginine, a competitive inhibitor with respect to L-arginine, reduced L-ornithine cooperativity. In the presence of spermidine, the L-ornithine saturation curve became increasingly sigmoidal, the Hill coefficient shifting from 2.5 in the absence of the inhibitor, to 3.5 in the presence of 20 mM spermidine. The L-arginine analog, L-homoarginine, was also a substrate of the succinyltransferase, and the saturation of the enzyme by this substrate was also cooperative. All these data confirmed the allosteric nature of the enzyme. Moreover, a mutant growing faster on L-ornithine than the parent strain had a modified succinyltransferase with a reduced L-ornithine cooperativity. The fate of L-homoarginine was different depending on whether the succinyltransferase was induced or not; excreted succinylhomoarginine was found in cultures induced for the transferase activity whereas guanidinovalerate was excreted in non-induced cultures. The 'waste' of succinyl CoA, which could not be regenerated from the excreted succinylhomoarginine, explained the inhibition exerted by L-homoarginine on growth when ornithine or arginine was used as the growth medium. << Less

  Eur. J. Biochem. 224:853-861(1994) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Arginine catabolism and the arginine succinyltransferase pathway in Escherichia coli.

  Schneider B.L., Kiupakis A.K., Reitzer L.J.

  Arginine catabolism produces ammonia without transferring nitrogen to another compound, yet the only known pathway of arginine catabolism in Escherichia coli (through arginine decarboxylase) does not produce ammonia. Our aims were to find the ammonia-producing pathway of arginine catabolism in E. ... >> More

  Arginine catabolism produces ammonia without transferring nitrogen to another compound, yet the only known pathway of arginine catabolism in Escherichia coli (through arginine decarboxylase) does not produce ammonia. Our aims were to find the ammonia-producing pathway of arginine catabolism in E. coli and to examine its function. We showed that the only previously described pathway of arginine catabolism, which does not produce ammonia, accounted for only 3% of the arginine consumed. A search for another arginine catabolic pathway led to discovery of the ammonia-producing arginine succinyltransferase (AST) pathway in E. coli. Nitrogen limitation induced this pathway in both E. coli and Klebsiella aerogenes, but the mechanisms of activation clearly differed in these two organisms. We identified the E. coli gene for succinylornithine aminotransferase, the third enzyme of the AST pathway, which appears to be the first of an astCADBE operon. Its disruption prevented arginine catabolism, impaired ornithine utilization, and affected the synthesis of all the enzymes of the AST pathway. Disruption of astB eliminated succinylarginine dihydrolase activity and prevented arginine utilization but did not impair ornithine catabolism. Overproduction of AST enzymes resulted in faster growth with arginine and aspartate. We conclude that the AST pathway is necessary for aerobic arginine catabolism in E. coli and that at least one enzyme of this pathway contributes to ornithine catabolism. << Less

  J. Bacteriol. 180:4278-4286(1998) [PubMed] [EuropePMC]

  This publication is cited by 4 other entries.

• Cloning and characterization of the aru genes encoding enzymes of the catabolic arginine succinyltransferase pathway in Pseudomonas aeruginosa.

  Itoh Y.

  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 clone ... >> More

  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. << Less

  J. Bacteriol. 179:7280-7290(1997) [PubMed] [EuropePMC]

  This publication is cited by 5 other entries.