Abstract
The phenotype of certain mutations in pyrA, the gene encoding carbamylphosphate synthetase (CPSase), is expressed only in the presence od exogenous arginine. In unsupplemented media, synthesis of carbamylphosphate and growth was almost normal; in arginine-containing media, synthesis of carbamylphosphate stopped, as did growth, as a consequence of starvation for pyrimidine. Genetic and biochemical evidence suggests that arginine exerts this inhibition by repressing the synthesis of ornithine carbamyltransferase (OTCase), the intracellular presence of which is required for assembly of the unequal subunits and proper functioning of the mutant CPSase. After the addition of arginine to a culture of the mutant, CPSase activity (glutamine dependent) characteristic of the intact holoenzyme progressively decreased, whereas activity (ammonia dependent) characteristic of the free large (alpha) subunit increased. Extracts of mutant cells contain free small (beta) subunits, as demonstrated directly by in vitro complementation using purified alpha subunits from wild type. The mutant enzyme from cultures grown in the presence of arginine had a markedly decreased affinity for adenosine 5'-triphosphate. Mutations in argR that cause depressed synthesis of OTCase suppressed the phenotype, and a certain mutation in argI, the gene encoding OTCase, enhanced it. In vitro experiments using purified enzyme confirm the stimulatory effect of OTCase on the activity of mutant CPSase.
Full text
PDF








Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Abd-el-Al A., Ingraham J. L. Cold sensitivity and other phenotypes resulting from mutation in pyrA gene. J Biol Chem. 1969 Aug 10;244(15):4039–4045. [PubMed] [Google Scholar]
- Abd-el-Al A., Ingraham J. L. Control of carbamyl phosphate synthesis in Salmonella typhimurium. J Biol Chem. 1969 Aug 10;244(15):4033–4038. [PubMed] [Google Scholar]
- Abdelal A. T., Ingraham J. L. Carbamylphosphate synthetase from Salmonella typhimurium. Regulations, subunit composition, and function of the subunits. J Biol Chem. 1975 Jun 25;250(12):4410–4417. [PubMed] [Google Scholar]
- Beck C. F., Ingraham J. L. Location on the chromosome of Salmonella typhimurium of genes governing pyrimidine metabolism. Mol Gen Genet. 1971;111(4):303–316. doi: 10.1007/BF00569782. [DOI] [PubMed] [Google Scholar]
- Biswas C., Paulus H. Multivalent feedback inhibition of aspartokinase in Bacillus polymyxa. IV. Arrangement and function of the subunits. J Biol Chem. 1973 Apr 25;248(8):2894–2900. [PubMed] [Google Scholar]
- Celis T. F., Maas W. K. Studies on the mechanism of repression of arginine biosynthesis in Escherichia coli. IV. Further studies on the role of arginine transfer RNA repression of the enzymes of arginine biosynthesis. J Mol Biol. 1971 Nov 28;62(1):179–188. doi: 10.1016/0022-2836(71)90138-0. [DOI] [PubMed] [Google Scholar]
- Cunin R., Kelker N., Boyen A., Yang H., Zubay G., Glansdorff N., Maas W. K. Involvement of arginine in in vitro repression of transcription of arginine genes C, B and H in Escherichia coli K 12. Biochem Biophys Res Commun. 1976 Mar 22;69(2):377–382. doi: 10.1016/0006-291x(76)90532-5. [DOI] [PubMed] [Google Scholar]
- Jacoby G. A., Gorini L. A unitary account of the repression mechanism of arginine biosynthesis in Escherichia coli. I. The genetic evidence. J Mol Biol. 1969 Jan 14;39(1):73–87. doi: 10.1016/0022-2836(69)90334-9. [DOI] [PubMed] [Google Scholar]
- Kelln R. A., Foltermann K. F., O'Donovan G. A. Location of the argR gene on the chromosome of Salmonella typhimurium. Mol Gen Genet. 1975 Sep 8;139(4):277–284. doi: 10.1007/BF00267967. [DOI] [PubMed] [Google Scholar]
- Kemper J. Gene order and co-transduction in the leu-ara-fol-pyrA region of the Salmonella typhimurium linkage map. J Bacteriol. 1974 Jan;117(1):94–99. doi: 10.1128/jb.117.1.94-99.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Leisinger T., Vogel R. H., Vogel H. J. Repression-dependent alteration of an arginine enzyme in Escherichia coli. Proc Natl Acad Sci U S A. 1969 Oct;64(2):686–692. doi: 10.1073/pnas.64.2.686. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Levine R. L., Kretchmer N. Conversion of carbamoyl phosphate to hydroxyurea. An assay for carbamoylphosphate synthetase. Anal Biochem. 1971 Aug;42(2):324–337. doi: 10.1016/0003-2697(71)90044-3. [DOI] [PubMed] [Google Scholar]
- Mergeay M., Gigot D., Beckmann J., Glansdorff N., Piérard A. Physiology and genetics of carbamoylphosphate synthesis in Escherichia coli K12. Mol Gen Genet. 1974;133(4):299–316. doi: 10.1007/BF00332706. [DOI] [PubMed] [Google Scholar]
- Messenguy F., Penninckx M., Wiame J. M. Interaction between arginase and ornithine carbamoyltransferase in Saccharomyces cerevisiae. The regulatory site for ornithine. Eur J Biochem. 1971 Sep 24;22(2):277–286. doi: 10.1111/j.1432-1033.1971.tb01542.x. [DOI] [PubMed] [Google Scholar]
- PATTERSON M. S., GREENE R. C. MEASUREMENT OF LOW ENERGY BETA-EMITTERS IN AQUEOUS SOLUTION BY LIQUID SCINTILLATION COUNTING OF EMULSIONS. Anal Chem. 1965 Jun;37:854–857. doi: 10.1021/ac60226a017. [DOI] [PubMed] [Google Scholar]
- Piérard A., Glansdorff N., Yashphe J. Mutations affecting uridine monophosphate pyrophosphorylase or the argR gene in Escherichia coli. Effects on carbamoyl phosphate and pyrimidine biosynthesis and on uracil uptake. Mol Gen Genet. 1972;118(3):235–245. doi: 10.1007/BF00333460. [DOI] [PubMed] [Google Scholar]
- Prescott L. M., Jones M. E. Modified methods for the determination of carbamyl aspartate. Anal Biochem. 1969 Dec;32(3):408–419. doi: 10.1016/s0003-2697(69)80008-4. [DOI] [PubMed] [Google Scholar]
- Trotta P. P., Pinkus L. M., Haschemeyer R. H., Meister A. Reversible dissociation of the monomer of glutamine-dependent carbamyl phosphate synthetase into catalytically active heavy and light subunits. J Biol Chem. 1974 Jan 25;249(2):492–499. [PubMed] [Google Scholar]
- VOGEL H. J., BONNER D. M. Acetylornithinase of Escherichia coli: partial purification and some properties. J Biol Chem. 1956 Jan;218(1):97–106. [PubMed] [Google Scholar]
- VYAS S., MAAS W. K. Feedback inhibition of acetylglutamate synthetase by arginine in Escherichia coli. Arch Biochem Biophys. 1963 Mar;100:542–546. doi: 10.1016/0003-9861(63)90124-3. [DOI] [PubMed] [Google Scholar]