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Positive allosteric feedback regulation of the stringent response enzyme RelA by its product.

ABSTRACT: During the stringent response, Escherichia coli enzyme RelA produces the ppGpp alarmone, which in turn regulates transcription, translation and replication. We show that ppGpp dramatically increases the turnover rate of its own ribosome-dependent synthesis by RelA, resulting in direct positive regulation of an enzyme by its product. Positive allosteric regulation therefore constitutes a new mechanism of enzyme activation. By integrating the output of individual RelA molecules and ppGpp degradation pathways, this regulatory circuit contributes to a fast and coordinated transition to stringency.

SUBMITTER: Shyp V

PROVIDER: S-EPMC3432798 | biostudies-other | 2012 Sep

REPOSITORIES: biostudies-other

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Positive allosteric feedback regulation of the stringent response enzyme RelA by its product.

Shyp Viktoriya V Tankov Stoyan S Ermakov Andrey A Kudrin Pavel P English Brian P BP Ehrenberg Måns M Tenson Tanel T Elf Johan J Hauryliuk Vasili V

EMBO reports 20120720 9

During the stringent response, Escherichia coli enzyme RelA produces the ppGpp alarmone, which in turn regulates transcription, translation and replication. We show that ppGpp dramatically increases the turnover rate of its own ribosome-dependent synthesis by RelA, resulting in direct positive regulation of an enzyme by its product. Positive allosteric regulation therefore constitutes a new mechanism of enzyme activation. By integrating the output of individual RelA molecules and ppGpp degradati ...[more]

PMID: 22814757

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The Borrelia burgdorferi RelA/SpoT Homolog and Stringent Response Regulate Survival in the Tick Vector and Global Gene Expression during Starvation.

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