Mechanisms of σ54-Dependent Transcription Initiation and Regulation. Issue 20 (20th September 2019)

• Record Type: Journal Article
• Authors: Danson, Amy E.; Jovanovic, Milija; Buck, Martin; Zhang, Xiaodong
• Is Part Of: Journal of molecular biology. Volume 431:Issue 20(2019)
• Page Start: 3960
• Page End: 3974
• Publication Date: 2019-09-20
• Subjects: bEBPs bacterial enhancer-binding proteins -- ELH extra-long helix -- HTH helix-turn-helix -- RNAP RNA polymerase -- RPc closed promoter complex -- RPi intermediate promoter complex -- RPip intermediate complex with partially loaded DNA -- RPo open promoter complex -- RPitc initial transcribing complex -- T- template strand; RNA polymerase -- sigma factors -- bacterial enhancer-binding proteins -- transcription bubble -- transcription regulation; Molecular biology -- Periodicals; Biology -- Periodicals; Biochemistry -- Periodicals; Bacteriology -- Periodicals; Molecular Biology -- Periodicals; Biochemistry -- Periodicals; Biologie moléculaire -- Périodiques; Biologie -- Périodiques; Biochimie -- Périodiques; Moleculaire biologie; Biochemistry; Biology; Molecular biology; Periodicals; 572.805
• DOI: 10.1016/j.jmb.2019.04.022
• Languages: English
• ISSNs: 0022-2836

Abstract

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 σ factor, σ 54, has a specific role in stress responses. Unlike σ 70 -dependent transcription, which often can spontaneously proceed to initiation, σ 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 σ 54 system with both x-ray crystallography and cryo electron microscopy, furthering our understanding of σ 54 -dependent transcription initiation and DNA opening. Comparisons with σ 70 and eukaryotic polymerases reveal unique and common features during transcription initiation. Graphical Abstract: Unlabelled Image Highlights: Mechanism of transcription inhibition by σ 54 Coupled load and unwind model for transcription initiation Role of bacterial enhancer-binding proteins in isomerization to the open complex Comparison of structural and functional differences between σ 70 and σ 54