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Mechanisms of ?54-Dependent Transcription Initiation and Regulation.

ABSTRACT: Cellular RNA polymerase is a multi-subunit macromolecular assembly responsible for gene transcription, a highly regulated process conserved from bacteria to humans. In bacteria, sigma factors are employed to mediate gene-specific expression in response to a variety of environmental conditions. The major variant ? factor, ?54, has a specific role in stress responses. Unlike ?70-dependent transcription, which often can spontaneously proceed to initiation, ?54-dependent transcription requires an additional ATPase protein for activation. As a result, structures of a number of distinct functional states during the dynamic process of transcription initiation have been captured using the ?54 system with both x-ray crystallography and cryo electron microscopy, furthering our understanding of ?54-dependent transcription initiation and DNA opening. Comparisons with ?70 and eukaryotic polymerases reveal unique and common features during transcription initiation.

SUBMITTER: Danson AE

PROVIDER: S-EPMC7057263 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

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Mechanisms of σ54-Dependent Transcription Initiation and Regulation.

Danson Amy E AE Jovanovic Milija M Buck Martin M Zhang Xiaodong X

Journal of molecular biology 20190425 20

Cellular RNA polymerase is a multi-subunit macromolecular assembly responsible for gene transcription, a highly regulated process conserved from bacteria to humans. In bacteria, sigma factors are employed to mediate gene-specific expression in response to a variety of environmental conditions. The major variant σ factor, σ54, has a specific role in stress responses. Unlike σ70-dependent transcription, which often can spontaneously proceed to initiation, σ54-depen ...[more]

PMID: 31029702

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