Operator constitutive mutations in the leucine operon of Salmonella typhimurium.
نویسندگان
چکیده
N a previous communication (CALVO, FREUNDLICH and UMBARGER 1969), a I group of Salmonella typhimurium mutants was described as having the following properties. They were resistant to an analog of leucine, 5’,5’,5’-trifluoroDL-leucine (RENNERT and ANKER 1963), excreted leucine, had constitutive and derepressed levels of enzymes involved in leucine biosynthesis, and they had mutant sites linked to the leucine operon. This paper describes in more detail the properties of these mutants and the map position of their mutant sites.
منابع مشابه
Regulation of branched-chain amino acid biosynthesis in Salmonella typhimurium: isolation of regulatory mutants.
5',5',5'-Trifluoro-dl-leucine inhibited the activity of alpha-isopropylmalate synthetase (the initial enzyme unique to leucine biosynthesis) as well as the growth of Salmonella typhimurium. Mutants of S. typhimurium resistant to the analogue were isolated and characterized. In most cases, they overproduced and excreted leucine or leucine, valine, and isoleucine as a result of an alteration in t...
متن کاملExpression of the leucine operon.
Burns, R. O. (Cold Spring Harbor Laboratories of Quantitative Biology, Cold Spring Harbor, N.Y.), J. Calvo, P. Margolin, and H. E. Umbarger. Expression of the leucine operon. J. Bacteriol. 91:1570-1576. 1966.-The four genes which specify the structure of the three enzymes specifically involved in the biosynthesis of leucine in Salmonella typhimurium constitute a single operon. Three types of co...
متن کاملHistidine regulatory mutants in Salmonella typhimurium. I. Isolation and general properties.
At least four genetically distinct classes of mutations give rise to triazolealanine resistance in SaZmoneZZa typhimurium. Each class studied affects regulation of the histidine operon. Mutants of one class, GO, are located at one end of the histidine operon. This class may be similar to operator constitutive mutants studied in other systems. At least two genetic sites are present in this regio...
متن کاملEvidence for an altered operator specificity: catabolite repression control of the leucine operon in Salmonella typhimurium.
A mutation, GD-1, in the leucine operon imposed unusual growth characteristics upon a leucine auxotrophic strain bearing the leucine operator mutation, leu-500. The strain with the GD-1 mutation was able to grow on a minimal salts medium when citrate was the sole carbon source, but required leucine when glucose was present. Tests with a large number of carbohydrates suggest that in the strain b...
متن کاملA fine structure map of the salmonella histidine operator-promoter.
Over 100 regulatory mutations linked to the histidine (his) operon of S. typhimurium have been isolated. They all map in a region estimated to be several hundred base pairs in length located at one end of the his operon ("the hisO region"). The mutations are located at sixteen recombinationally separable sites or are deletions encompassing several sites. Data obtained from pairs of reciprocal t...
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ورودعنوان ژورنال:
- Genetics
دوره 61 4 شماره
صفحات -
تاریخ انتشار 1969