Control of acetohydroxy acid synthetase in Escherichia coli 9723.
Biochemistry
; 17(16): 3292-7, 1978 Aug 08.
Article
en En
| MEDLINE
| ID: mdl-356876
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.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Acetolactato Sintasa
/
Escherichia coli
/
Oxo-Ácido-Liasas
Idioma:
En
Revista:
Biochemistry
Año:
1978
Tipo del documento:
Article
Pais de publicación:
Estados Unidos