8ac1
From Proteopedia
RNA polymerase at U-rich pause bound to non-regulatory RNA - inactive, open clamp state
Structural highlights
FunctionRPOA_ECOLI DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit plays an important role in subunit assembly since its dimerization is the first step in the sequential assembly of subunits to form the holoenzyme.[HAMAP-Rule:MF_00059] Publication Abstract from PubMedRNA can regulate its own synthesis without auxiliary proteins. For example, U-rich RNA sequences signal RNA polymerase (RNAP) to pause transcription and are required for transcript release at intrinsic terminators in all kingdoms of life. In contrast, the regulatory RNA putL suppresses pausing and termination in cis. However, how nascent RNA modulates its own synthesis remains largely unknown. We present cryo-EM reconstructions of RNAP captured during transcription of putL variants or an unrelated sequence at a U-rich pause site. Our results suggest how putL suppresses pausing and promotes its synthesis. We demonstrate that transcribing a U-rich sequence, a ubiquitous trigger of intrinsic termination, promotes widening of the RNAP nucleic-acid-binding channel. Widening destabilizes RNAP interactions with DNA and RNA to facilitate transcript dissociation reminiscent of intrinsic transcription termination. Surprisingly, RNAP remains bound to DNA after transcript release. Our results provide the structural framework to understand RNA-mediated intrinsic transcription termination. Structural insights into RNA-mediated transcription regulation in bacteria.,Dey S, Batisse C, Shukla J, Webster MW, Takacs M, Saint-Andre C, Weixlbaumer A Mol Cell. 2022 Oct 20;82(20):3885-3900.e10. doi: 10.1016/j.molcel.2022.09.020. , Epub 2022 Oct 10. PMID:36220101[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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