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CryoEM structure of the transcription termination factor Rho from Mycobacterium tuberculosisCryoEM structure of the transcription termination factor Rho from Mycobacterium tuberculosis
Structural highlights
Function[RHO_MYCTU] Facilitates transcription termination by a mechanism that involves Rho binding to the nascent RNA, activation of Rho's RNA-dependent ATPase activity, and release of the mRNA from the DNA template. Shows poor RNA-dependent ATP hydrolysis and inefficient DNA-RNA unwinding activities, but exhibits robust and fast transcription termination, which suggests that the transcription termination function of M.tuberculosis Rho is not correlated with its helicase/translocase activities and that these functions may not be important for its RNA release process.[HAMAP-Rule:MF_01884][1] Publication Abstract from PubMedThe bacterial Rho factor is a ring-shaped motor triggering genome-wide transcription termination and R-loop dissociation. Rho is essential in many species, including in Mycobacterium tuberculosis where rho gene inactivation leads to rapid death. Yet, the M. tuberculosis Rho [MtbRho] factor displays poor NTPase and helicase activities, and resistance to the natural Rho inhibitor bicyclomycin [BCM] that remain unexplained. To address these issues, we solved the cryo-EM structure of MtbRho at 3.3 A resolution. The MtbRho hexamer is poised into a pre-catalytic, open-ring state wherein specific contacts stabilize ATP in intersubunit ATPase pockets, thereby explaining the cofactor preference of MtbRho. We reveal a leucine-to-methionine substitution that creates a steric bulk in BCM binding cavities near the positions of ATP gamma-phosphates, and confers resistance to BCM at the expense of motor efficiency. Our work contributes to explain the unusual features of MtbRho and provides a framework for future antibiotic development. Cryo-EM structure of transcription termination factor Rho from Mycobacterium tuberculosis reveals bicyclomycin resistance mechanism.,Saridakis E, Vishwakarma R, Lai-Kee-Him J, Martin K, Simon I, Cohen-Gonsaud M, Coste F, Bron P, Margeat E, Boudvillain M Commun Biol. 2022 Feb 9;5(1):120. doi: 10.1038/s42003-022-03069-6. PMID:35140348[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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