Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1974 Dec;120(3):1068-77.
doi: 10.1128/jb.120.3.1068-1077.1974.

Structural genes for a newly recognized acetolactate synthase in Escherichia coli K-12

Structural genes for a newly recognized acetolactate synthase in Escherichia coli K-12

M De Felice et al. J Bacteriol. 1974 Dec.

Abstract

Evidence is reported that shows the presence in Escherichia coli K-12 of a newly found acetolactate synthase. This enzyme is the product of two genes, ilvH and ilvI, both located very close to leu. Amber mutations have been found in both genes and therefore their products are polypeptides. Mutations in the ilvH gene cause the appearance of an acetolactate synthase activity which is relatively resistant to valine inhibition and can be separated by adsorption on hydroxylapatite from another activity present in the extract and more sensitive to valine inhibition than the former. A mutant altered in the ilvI gene was isolated among the revertants sensitive to valine inhibition of an ilvH mutant. Such a mutant lacks the resistant acetolactate synthase. A temperature-sensitive revertant of the ilvI mutant contained a temperature-sensitive acetolactate synthase. Thus ilvI is the structural gene for a specific acetolactate synthase. The activity of the ilvH gene product has been measured by adding an extract containing it to a purified ilvI acetolactate synthase, which, upon incubation, became more sensitive to valine inhibition. Conversely, a valine-sensitive acetolactate synthase (the product of the ilvH and the ilvI genes) became more resistant to valine inhibition upon incubation with an extract of a strain containing a missense ilvH gene product.

PubMed Disclaimer

References

    1. J Bacteriol. 1971 Apr;106(1):204-12 - PubMed
    1. Genetics. 1965 Mar;51(3):341-9 - PubMed
    1. J Bacteriol. 1973 Nov;116(2):751-6 - PubMed
    1. Proc Natl Acad Sci U S A. 1968 May;60(1):160-7 - PubMed
    1. J Bacteriol. 1974 Oct;120(1):536-8 - PubMed

LinkOut - more resources