Control of acetohydroxy acid synthetase in Escherichia coli 9723

Autor:	Dan A. Wiginton, William Shive
Rok vydání:	1978
Předmět:	chemistry.chemical_classification Chemistry Mutant Oxo-Acid-Lyases medicine.disease_cause Biochemistry Amino acid Acetolactate Synthase Acetohydroxy Acid Synthetase Enzyme Valine Mutation Escherichia coli medicine Enzyme Repression Isoleucine Leucine
Zdroj:	Biochemistry. 17:3292-3297
ISSN:	1520-4995 0006-2960
DOI:	10.1021/bi00609a018
Popis:	A method by which three acetohydroxy acid synthetase activities are separated from extracts of Escherichia coli 9723 has been developed. Isoleucine specifically represses synthesis of one of the enzymes, which is not sensitive to valine inhibition, and isoleucine also simultaneously enhances the production of a second activity, which is valine inhibitable. The valine-inhibitable activity is repressed by leucine and valine, a combination of which is more effective than either alone. The third acetohydroxy acid synthetase, which is more active at pH 6 than at 8, is not controlled by the branched-chain amino acids. In a mutant of E. coli 9723 selected for the ability of valine to inhibit growth, the isoleucine-repressible acetohydroxy acid synthetase activity was no longer present, but isoleucine addition still resulted in enhanced production of the valine-inhibitable activity.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f4d7dce826d15938a9c1df4a0c8598ac https://doi.org/10.1021/bi00609a018 Zobrazit plný text záznamu