Biosynthesis of isoleucine and valine in Rhodopseudomonas spheroides: regulation of threonine deaminase activity.
نویسنده
چکیده
The activities of threonine deaminase, acetohydroxy acid synthetase, acetohydroxy acid reductoisomerase, dihydroxy acid dehydrase, and transaminase B were detected in cell-free extracts of Rhodopseudomonas spheroides. No significant repression or derepression of threonine deaminase activity was observed.
منابع مشابه
Purification and feedback control of threonine deaminase activity of Rhodopseudomonas spheroides.
1. Threonine deaminase has been purified about 1400fold from extracts of the photosynthetic bacterium Rhodopseudomonas spheroides by ammonium sulfate fractionation and by chromatography on DEAE-cellulose and hydroxylapatite columns. The purified enzyme is almost completely resolved with respect to bound coenzyme, and the activity of holoenzyme is specific for pyridoxal phosphate. The enzyme is ...
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Regulation of four of the enzymes required for isoleucine and valine biosynthesis in Acinetobacter was studied. A three- to fourfold derepression of acetohydroxyacid synthetase was routinely observed in two different wild-type strains when grown in minimal medium relative to cells grown in minimal medium supplemented with leucine, valine, and isoleucine. A similar degree of synthetase derepress...
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Regulation of the biosynthesis of four of the five enzymes of the isoleucine-valine pathway was studied in Saccharomyces cerevisiae. A method is described for limiting the growth of a leucine auxotroph by using valine as a competitor for the permease. Limitation for isoleucine and valine was accomplished by the use of peptides containing these amino acids conjugated with glycine as nutritional ...
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Kerwar, Suresh S. (Oregon State University, Corvallis), Vernon, H. Cheldelin, and L. W. Parks. Valine-isoleucine metabolism in Acetobacter suboxydans and the inhibition of growth by valine. J. Bacteriol. 88:179-186. 1964.-Extracts of Acetobacter suboxydans can synthesize valine and isoleucine via acetolactate and acetohydroxybutyrate, respectively. The amounts of these amino acids synthesized f...
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عنوان ژورنال:
- Journal of bacteriology
دوره 105 3 شماره
صفحات -
تاریخ انتشار 1971