1
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Ye J, Kan CH, Yang X, Ma C. Inhibition of bacterial RNA polymerase function and protein-protein interactions: a promising approach for next-generation antibacterial therapeutics. RSC Med Chem 2024; 15:1471-1487. [PMID: 38784472 PMCID: PMC11110800 DOI: 10.1039/d3md00690e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/25/2024] [Indexed: 05/25/2024] Open
Abstract
The increasing prevalence of multidrug-resistant pathogens necessitates the urgent development of new antimicrobial agents with innovative modes of action for the next generation of antimicrobial therapy. Bacterial transcription has been identified and widely studied as a viable target for antimicrobial development. The main focus of these studies has been the discovery of inhibitors that bind directly to the core enzyme of RNA polymerase (RNAP). Over the past two decades, substantial advancements have been made in understanding the properties of protein-protein interactions (PPIs) and gaining structural insights into bacterial RNAP and its associated factors. This has led to the crucial role of computational methods in aiding the identification of new PPI inhibitors to affect the RNAP function. In this context, bacterial transcriptional PPIs present promising, albeit challenging, targets for the creation of new antimicrobials. This review will succinctly outline the structural foundation of bacterial transcription networks and provide a summary of the known small molecules that target transcription PPIs.
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Affiliation(s)
- Jiqing Ye
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Kowloon Hong Kong SAR China
- School of Pharmacy, Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Medical University Hefei 230032 China
| | - Cheuk Hei Kan
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital Shatin Hong Kong SAR China
| | - Xiao Yang
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital Shatin Hong Kong SAR China
| | - Cong Ma
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University Kowloon Hong Kong SAR China
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2
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Qayyum MZ, Imashimizu M, Leanca M, Vishwakarma RK, Riaz-Bradley A, Yuzenkova Y, Murakami KS. Structure and function of the Si3 insertion integrated into the trigger loop/helix of cyanobacterial RNA polymerase. Proc Natl Acad Sci U S A 2024; 121:e2311480121. [PMID: 38354263 PMCID: PMC10895346 DOI: 10.1073/pnas.2311480121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 01/17/2024] [Indexed: 02/16/2024] Open
Abstract
Cyanobacteria and evolutionarily related chloroplasts of algae and plants possess unique RNA polymerases (RNAPs) with characteristics that distinguish them from canonical bacterial RNAPs. The largest subunit of cyanobacterial RNAP (cyRNAP) is divided into two polypeptides, β'1 and β'2, and contains the largest known lineage-specific insertion domain, Si3, located in the middle of the trigger loop and spanning approximately half of the β'2 subunit. In this study, we present the X-ray crystal structure of Si3 and the cryo-EM structures of the cyRNAP transcription elongation complex plus the NusG factor with and without incoming nucleoside triphosphate (iNTP) bound at the active site. Si3 has a well-ordered and elongated shape that exceeds the length of the main body of cyRNAP, fits into cavities of cyRNAP in the absence of iNTP bound at the active site and shields the binding site of secondary channel-binding proteins such as Gre and DksA. A small transition from the trigger loop to the trigger helix upon iNTP binding results in a large swing motion of Si3; however, this transition does not affect the catalytic activity of cyRNAP due to its minimal contact with cyRNAP, NusG, or DNA. This study provides a structural framework for understanding the evolutionary significance of these features unique to cyRNAP and chloroplast RNAP and may provide insights into the molecular mechanism of transcription in specific environment of photosynthetic organisms and organelle.
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Affiliation(s)
- M. Zuhaib Qayyum
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA16802
| | - Masahiko Imashimizu
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA16802
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba305-8565, Japan
| | - Miron Leanca
- The Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon TyneNE2 4HH, United Kingdom
| | - Rishi K. Vishwakarma
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA16802
| | - Amber Riaz-Bradley
- The Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon TyneNE2 4HH, United Kingdom
| | - Yulia Yuzenkova
- The Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon TyneNE2 4HH, United Kingdom
| | - Katsuhiko S. Murakami
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA16802
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3
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Lou Y, Woodson SA. Co-transcriptional folding of the glmS ribozyme enables a rapid response to metabolite. Nucleic Acids Res 2024; 52:872-884. [PMID: 38000388 PMCID: PMC10810187 DOI: 10.1093/nar/gkad1120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/24/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
The glmS ribozyme riboswitch, located in the 5' untranslated region of the Bacillus subtilis glmS messenger RNA (mRNA), regulates cell wall biosynthesis through ligand-induced self-cleavage and decay of the glmS mRNA. Although self-cleavage of the refolded glmS ribozyme has been studied extensively, it is not known how early the ribozyme folds and self-cleaves during transcription. Here, we combine single-molecule fluorescence with kinetic modeling to show that self-cleavage can occur during transcription before the ribozyme is fully synthesized. Moreover, co-transcriptional folding of the RNA at a physiological elongation rate allows the ribozyme catalytic core to react without the downstream peripheral stability domain. Dimethyl sulfate footprinting further revealed how slow sequential folding favors formation of the native core structure through fraying of misfolded helices and nucleation of a native pseudoknot. Ribozyme self-cleavage at an early stage of transcription may benefit glmS regulation in B. subtilis, as it exposes the mRNA to exoribonuclease before translation of the open reading frame can begin. Our results emphasize the importance of co-transcriptional folding of RNA tertiary structure for cis-regulation of mRNA stability.
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Affiliation(s)
- Yuan Lou
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Sarah A Woodson
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
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4
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Qayyum MZ, Imashimizu M, Leanca M, Vishwakarma RK, Riaz-Bradley A, Yuzenkova Y, Murakami KS. Structure and function of the Si3 insertion integrated into the trigger loop/helix of cyanobacterial RNA polymerase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575193. [PMID: 38260627 PMCID: PMC10802570 DOI: 10.1101/2024.01.11.575193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Cyanobacteria and evolutionarily related chloroplasts of algae and plants possess unique RNA polymerases (RNAPs) with characteristics that distinguish from canonical bacterial RNAPs. The largest subunit of cyanobacterial RNAP (cyRNAP) is divided into two polypeptides, β'1 and β'2, and contains the largest known lineage-specific insertion domain, Si3, located in the middle of the trigger loop and spans approximately half of the β'2 subunit. In this study, we present the X-ray crystal structure of Si3 and the cryo-EM structures of the cyRNAP transcription elongation complex plus the NusG factor with and without incoming nucleoside triphosphate (iNTP) bound at the active site. Si3 has a well-ordered and elongated shape that exceeds the length of the main body of cyRNAP, fits into cavities of cyRNAP and shields the binding site of secondary channel-binding proteins such as Gre and DksA. A small transition from the trigger loop to the trigger helix upon iNTP binding at the active site results in a large swing motion of Si3; however, this transition does not affect the catalytic activity of cyRNAP due to its minimal contact with cyRNAP, NusG or DNA. This study provides a structural framework for understanding the evolutionary significance of these features unique to cyRNAP and chloroplast RNAP and may provide insights into the molecular mechanism of transcription in specific environment of photosynthetic organisms.
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Affiliation(s)
- M. Zuhaib Qayyum
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Current address: Protein Technologies Center, Inspiration4 Advanced Research Center, Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Masahiko Imashimizu
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, 305-8565 Japan
| | - Miron Leanca
- The Centre for Bacterial Cell Biology, Newcastle University, UK
| | - Rishi K. Vishwakarma
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | | | - Yulia Yuzenkova
- The Centre for Bacterial Cell Biology, Newcastle University, UK
| | - Katsuhiko S. Murakami
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, The Pennsylvania State University, University Park, PA 16802, USA
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5
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Zhou B, Xiong Y, Nevo Y, Kahan T, Yakovian O, Alon S, Bhattacharya S, Rosenshine I, Sinai L, Ben-Yehuda S. Dormant bacterial spores encrypt a long-lasting transcriptional program to be executed during revival. Mol Cell 2023; 83:4158-4173.e7. [PMID: 37949068 DOI: 10.1016/j.molcel.2023.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 08/16/2023] [Accepted: 10/12/2023] [Indexed: 11/12/2023]
Abstract
Sporulating bacteria can retreat into long-lasting dormant spores that preserve the capacity to germinate when propitious. However, how the revival transcriptional program is memorized for years remains elusive. We revealed that in dormant spores, core RNA polymerase (RNAP) resides in a central chromosomal domain, where it remains bound to a subset of intergenic promoter regions. These regions regulate genes encoding for most essential cellular functions, such as rRNAs and tRNAs. Upon awakening, RNAP recruits key transcriptional components, including sigma factor, and progresses to express the adjacent downstream genes. Mutants devoid of spore DNA-compacting proteins exhibit scattered RNAP localization and subsequently disordered firing of gene expression during germination. Accordingly, we propose that the spore chromosome is structured to preserve the transcriptional program by halting RNAP, prepared to execute transcription at the auspicious time. Such a mechanism may sustain long-term transcriptional programs in diverse organisms displaying a quiescent life form.
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Affiliation(s)
- Bing Zhou
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Yifei Xiong
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Yuval Nevo
- Info-CORE, Bioinformatics Unit of the I-CORE Computation Center at the Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Tamar Kahan
- Bioinformatics Unit, Faculty of Medicine, The Hebrew University of Jerusalem, 9112001 Jerusalem, Israel
| | - Oren Yakovian
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel; The Racah Institute of Physics, Faculty of Science, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel
| | - Sima Alon
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Saurabh Bhattacharya
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel
| | - Lior Sinai
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel.
| | - Sigal Ben-Yehuda
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O.B. 12272, 9112001 Jerusalem, Israel.
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6
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Delbeau M, Omollo EO, Froom R, Koh S, Mooney RA, Lilic M, Brewer JJ, Rock J, Darst SA, Campbell EA, Landick R. Structural and functional basis of the universal transcription factor NusG pro-pausing activity in Mycobacterium tuberculosis. Mol Cell 2023; 83:1474-1488.e8. [PMID: 37116494 PMCID: PMC10231689 DOI: 10.1016/j.molcel.2023.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 02/08/2023] [Accepted: 04/04/2023] [Indexed: 04/30/2023]
Abstract
Transcriptional pauses mediate regulation of RNA biogenesis. DNA-encoded pause signals trigger pausing by stabilizing RNA polymerase (RNAP) swiveling and inhibiting DNA translocation. The N-terminal domain (NGN) of the only universal transcription factor, NusG/Spt5, modulates pausing through contacts to RNAP and DNA. Pro-pausing NusGs enhance pauses, whereas anti-pausing NusGs suppress pauses. Little is known about pausing and NusG in the human pathogen Mycobacterium tuberculosis (Mtb). We report that MtbNusG is pro-pausing. MtbNusG captures paused, swiveled RNAP by contacts to the RNAP protrusion and nontemplate-DNA wedged between the NGN and RNAP gate loop. In contrast, anti-pausing Escherichia coli (Eco) NGN contacts the MtbRNAP gate loop, inhibiting swiveling and pausing. Using CRISPR-mediated genetics, we show that pro-pausing NGN is required for mycobacterial fitness. Our results define an essential function of mycobacterial NusG and the structural basis of pro- versus anti-pausing NusG activity, with broad implications for the function of all NusG orthologs.
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Affiliation(s)
- Madeleine Delbeau
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Expery O Omollo
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ruby Froom
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA; Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY 10065, USA
| | - Steven Koh
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Rachel A Mooney
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mirjana Lilic
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Joshua J Brewer
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Jeremy Rock
- Laboratory of Host-Pathogen Biology, The Rockefeller University, New York, NY 10065, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA.
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10065, USA.
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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7
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Kang JY, Mishanina TV, Bao Y, Chen J, Llewellyn E, Liu J, Darst SA, Landick R. An ensemble of interconverting conformations of the elemental paused transcription complex creates regulatory options. Proc Natl Acad Sci U S A 2023; 120:e2215945120. [PMID: 36795753 PMCID: PMC9974457 DOI: 10.1073/pnas.2215945120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/10/2023] [Indexed: 02/17/2023] Open
Abstract
Transcriptional pausing underpins the regulation of cellular RNA synthesis, but its mechanism remains incompletely understood. Sequence-specific interactions of DNA and RNA with the dynamic, multidomain RNA polymerase (RNAP) trigger reversible conformational changes at pause sites that temporarily interrupt the nucleotide addition cycle. These interactions initially rearrange the elongation complex (EC) into an elemental paused EC (ePEC). ePECs can form longer-lived PECs by further rearrangements or interactions of diffusible regulators. For both bacterial and mammalian RNAPs, a half-translocated state in which the next DNA template base fails to load into the active site appears central to the ePEC. Some RNAPs also swivel interconnected modules that may stabilize the ePEC. However, it is unclear whether swiveling and half-translocation are requisite features of a single ePEC state or if multiple ePEC states exist. Here, we use cryo-electron microscopy (cryo-EM) analysis of ePECs with different RNA-DNA sequences combined with biochemical probes of ePEC structure to define an interconverting ensemble of ePEC states. ePECs occupy either pre- or half-translocated states but do not always swivel, indicating that difficulty in forming the posttranslocated state at certain RNA-DNA sequences may be the essence of the ePEC. The existence of multiple ePEC conformations has broad implications for transcriptional regulation.
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Affiliation(s)
- Jin Young Kang
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon34141, Republic of Korea
| | - Tatiana V. Mishanina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA92093
| | - Yu Bao
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI53706
| | - James Chen
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - Eliza Llewellyn
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - James Liu
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI53706
| | - Seth A. Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY10065
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI53706
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI53706
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8
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Allosteric mechanism of transcription inhibition by NusG-dependent pausing of RNA polymerase. Proc Natl Acad Sci U S A 2023; 120:e2218516120. [PMID: 36745813 PMCID: PMC9963633 DOI: 10.1073/pnas.2218516120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
NusG is a transcription elongation factor that stimulates transcription pausing in Gram+ bacteria including B. subtilis by sequence-specific interaction with a conserved pause-inducing -11TTNTTT-6 motif found in the non-template DNA (ntDNA) strand within the transcription bubble. To reveal the structural basis of NusG-dependent pausing, we determined a cryo-EM structure of a paused transcription complex (PTC) containing RNA polymerase (RNAP), NusG, and the TTNTTT motif in the ntDNA strand. The interaction of NusG with the ntDNA strand rearranges the transcription bubble by positioning three consecutive T residues in a cleft between NusG and the β-lobe domain of RNAP. We revealed that the RNAP swivel module rotation (swiveling), which widens (swiveled state) and narrows (non-swiveled state) a cleft between NusG and the β-lobe, is an intrinsic motion of RNAP and is directly linked to trigger loop (TL) folding, an essential conformational change of all cellular RNAPs for the RNA synthesis reaction. We also determined cryo-EM structures of RNAP escaping from the paused transcription state. These structures revealed the NusG-dependent pausing mechanism by which NusG-ntDNA interaction inhibits the transition from swiveled to non-swiveled states, thereby preventing TL folding and RNA synthesis allosterically. This motion is also reduced by the formation of an RNA hairpin within the RNA exit channel. Thus, the pause half-life can be modulated by the strength of the NusG-ntDNA interaction and/or the stability of the RNA hairpin. NusG residues that interact with the TTNTTT motif are widely conserved in bacteria, suggesting that NusG-dependent pausing is widespread.
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9
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Takada H, Mandell ZF, Yakhnin H, Glazyrina A, Chiba S, Kurata T, Wu KJY, Tresco BIC, Myers AG, Aktinson GC, Babitzke P, Hauryliuk V. Expression of Bacillus subtilis ABCF antibiotic resistance factor VmlR is regulated by RNA polymerase pausing, transcription attenuation, translation attenuation and (p)ppGpp. Nucleic Acids Res 2022; 50:6174-6189. [PMID: 35699226 PMCID: PMC9226507 DOI: 10.1093/nar/gkac497] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/22/2022] [Accepted: 05/26/2022] [Indexed: 12/14/2022] Open
Abstract
Since antibiotic resistance is often associated with a fitness cost, bacteria employ multi-layered regulatory mechanisms to ensure that expression of resistance factors is restricted to times of antibiotic challenge. In Bacillus subtilis, the chromosomally-encoded ABCF ATPase VmlR confers resistance to pleuromutilin, lincosamide and type A streptogramin translation inhibitors. Here we show that vmlR expression is regulated by translation attenuation and transcription attenuation mechanisms. Antibiotic-induced ribosome stalling during translation of an upstream open reading frame in the vmlR leader region prevents formation of an anti-antiterminator structure, leading to the formation of an antiterminator structure that prevents intrinsic termination. Thus, transcription in the presence of antibiotic induces vmlR expression. We also show that NusG-dependent RNA polymerase pausing in the vmlR leader prevents leaky expression in the absence of antibiotic. Furthermore, we demonstrate that induction of VmlR expression by compromised protein synthesis does not require the ability of VmlR to rescue the translational defect, as exemplified by constitutive induction of VmlR by ribosome assembly defects. Rather, the specificity of induction is determined by the antibiotic's ability to stall the ribosome on the regulatory open reading frame located within the vmlR leader. Finally, we demonstrate the involvement of (p)ppGpp-mediated signalling in antibiotic-induced VmlR expression.
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Affiliation(s)
- Hiraku Takada
- Faculty of Life Sciences, Kyoto Sangyo University and Institute for Protein Dynamics, Kamigamo, Motoyama, Kita-ku, Kyoto 603-8555, Japan.,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden.,Department of Molecular Biology, Umeå University, Building 6K, 6L University Hospital Area, 90187 Umeå, Sweden
| | - Zachary F Mandell
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | - Anastasiya Glazyrina
- Department of Molecular Biology, Umeå University, Building 6K, 6L University Hospital Area, 90187 Umeå, Sweden
| | - Shinobu Chiba
- Faculty of Life Sciences, Kyoto Sangyo University and Institute for Protein Dynamics, Kamigamo, Motoyama, Kita-ku, Kyoto 603-8555, Japan
| | - Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Kelvin J Y Wu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Ben I C Tresco
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Andrew G Myers
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Gemma C Aktinson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, USA
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden.,Department of Molecular Biology, Umeå University, Building 6K, 6L University Hospital Area, 90187 Umeå, Sweden.,University of Tartu, Institute of Technology, 50411, Tartu, Estonia
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10
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Pukhrambam C, Molodtsov V, Kooshkbaghi M, Tareen A, Vu H, Skalenko KS, Su M, Yin Z, Winkelman JT, Kinney JB, Ebright RH, Nickels BE. Structural and mechanistic basis of σ-dependent transcriptional pausing. Proc Natl Acad Sci U S A 2022; 119:e2201301119. [PMID: 35653571 PMCID: PMC9191641 DOI: 10.1073/pnas.2201301119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/26/2022] [Indexed: 12/20/2022] Open
Abstract
In σ-dependent transcriptional pausing, the transcription initiation factor σ, translocating with RNA polymerase (RNAP), makes sequence-specific protein–DNA interactions with a promoter-like sequence element in the transcribed region, inducing pausing. It has been proposed that, in σ-dependent pausing, the RNAP active center can access off-pathway “backtracked” states that are substrates for the transcript-cleavage factors of the Gre family and on-pathway “scrunched” states that mediate pause escape. Here, using site-specific protein–DNA photocrosslinking to define positions of the RNAP trailing and leading edges and of σ relative to DNA at the λPR′ promoter, we show directly that σ-dependent pausing in the absence of GreB in vitro predominantly involves a state backtracked by 2–4 bp, and σ-dependent pausing in the presence of GreB in vitro and in vivo predominantly involves a state scrunched by 2–3 bp. Analogous experiments with a library of 47 (∼16,000) transcribed-region sequences show that the state scrunched by 2–3 bp—and only that state—is associated with the consensus sequence, T−3N−2Y−1G+1, (where −1 corresponds to the position of the RNA 3′ end), which is identical to the consensus for pausing in initial transcription and which is related to the consensus for pausing in transcription elongation. Experiments with heteroduplex templates show that sequence information at position T−3 resides in the DNA nontemplate strand. A cryoelectron microscopy structure of a complex engaged in σ-dependent pausing reveals positions of DNA scrunching on the DNA nontemplate and template strands and suggests that position T−3 of the consensus sequence exerts its effects by facilitating scrunching.
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Affiliation(s)
- Chirangini Pukhrambam
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Genetics, Rutgers University, Piscataway, NJ 08854
| | - Vadim Molodtsov
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854
| | - Mahdi Kooshkbaghi
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Ammar Tareen
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Hoa Vu
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Genetics, Rutgers University, Piscataway, NJ 08854
| | - Kyle S. Skalenko
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Genetics, Rutgers University, Piscataway, NJ 08854
| | - Min Su
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109
| | - Zhou Yin
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854
| | - Jared T. Winkelman
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Genetics, Rutgers University, Piscataway, NJ 08854
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854
| | - Justin B. Kinney
- Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724
| | - Richard H. Ebright
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854
| | - Bryce E. Nickels
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ 08854
- Department of Genetics, Rutgers University, Piscataway, NJ 08854
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11
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Qayyum MZ, Molodtsov V, Renda A, Murakami KS. Structural basis of RNA polymerase recycling by the Swi2/Snf2 family of ATPase RapA in Escherichia coli. J Biol Chem 2021; 297:101404. [PMID: 34774797 PMCID: PMC8666675 DOI: 10.1016/j.jbc.2021.101404] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 11/02/2021] [Accepted: 11/09/2021] [Indexed: 01/27/2023] Open
Abstract
After transcription termination, cellular RNA polymerases (RNAPs) are occasionally trapped on DNA, impounded in an undefined post-termination complex (PTC), limiting the free RNAP pool and subsequently leading to inefficient transcription. In Escherichia coli, a Swi2/Snf2 family of ATPase called RapA is known to be involved in countering such inefficiency through RNAP recycling; however, the precise mechanism of this recycling is unclear. To better understand its mechanism, here we determined the structures of two sets of E. coli RapA–RNAP complexes, along with the RNAP core enzyme and the elongation complex, using cryo-EM. These structures revealed the large conformational changes of RNAP and RapA upon their association that has been implicated in the hindrance of PTC formation. Our results along with DNA-binding assays reveal that although RapA binds RNAP away from the DNA-binding main channel, its binding can allosterically close the RNAP clamp, thereby preventing its nonspecific DNA binding and PTC formation. Taken together, we propose that RapA acts as a guardian of RNAP by which RapA prevents nonspecific DNA binding of RNAP without affecting the binding of promoter DNA recognition σ factor, thereby enhancing RNAP recycling.
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Affiliation(s)
- M Zuhaib Qayyum
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Vadim Molodtsov
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Andrew Renda
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Katsuhiko S Murakami
- Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Center for Structural Biology, Pennsylvania State University, University Park, Pennsylvania, USA.
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12
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Abstract
Cellular life depends on transcription of DNA by RNA polymerase to express genetic information. RNA polymerase has evolved not just to read information from DNA and write it to RNA but also to sense and process information from the cellular and extracellular environments. Much of this information processing occurs during transcript elongation, when transcriptional pausing enables regulatory decisions. Transcriptional pauses halt RNA polymerase in response to DNA and RNA sequences and structures at locations and times that help coordinate interactions with small molecules and transcription factors important for regulation. Four classes of transcriptional pause signals are now evident after decades of study: elemental pauses, backtrack pauses, hairpin-stabilized pauses, and regulator-stabilized pauses. In this review, I describe current understanding of the molecular mechanisms of these four classes of pause signals, remaining questions about how RNA polymerase responds to pause signals, and the many exciting directions now open to understand pausing and the regulation of transcript elongation on a genome-wide scale. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Robert Landick
- Department of Biochemistry and Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA;
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13
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Qian J, Dunlap D, Finzi L. Basic mechanisms and kinetics of pause-interspersed transcript elongation. Nucleic Acids Res 2021; 49:15-24. [PMID: 33330935 PMCID: PMC7797061 DOI: 10.1093/nar/gkaa1182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/16/2020] [Accepted: 11/19/2020] [Indexed: 11/13/2022] Open
Abstract
RNA polymerase pausing during elongation is an important mechanism in the regulation of gene expression. Pausing along DNA templates is thought to be induced by distinct signals encoded in the nucleic acid sequence and halt elongation complexes to allow time for necessary co-transcriptional events. Pausing signals have been classified as those producing short-lived elemental, long-lived backtracked, or hairpin-stabilized pauses. In recent years, structural microbiology and single-molecule studies have significantly advanced our understanding of the paused states, but the dynamics of these states are still uncertain, although several models have been proposed to explain the experimentally observed pausing behaviors. This review summarizes present knowledge about the paused states, discusses key discrepancies among the kinetic models and their basic assumptions, and highlights the importance and challenges in constructing theoretical models that may further our biochemical understanding of transcriptional pausing.
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Affiliation(s)
- Jin Qian
- Physics, Emory University, Atlanta, GA 30307, USA
| | - David Dunlap
- Physics, Emory University, Atlanta, GA 30307, USA
| | - Laura Finzi
- Physics, Emory University, Atlanta, GA 30307, USA
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14
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Wang B, Artsimovitch I. NusG, an Ancient Yet Rapidly Evolving Transcription Factor. Front Microbiol 2021; 11:619618. [PMID: 33488562 PMCID: PMC7819879 DOI: 10.3389/fmicb.2020.619618] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/07/2020] [Indexed: 12/19/2022] Open
Abstract
Timely and accurate RNA synthesis depends on accessory proteins that instruct RNA polymerase (RNAP) where and when to start and stop transcription. Among thousands of transcription factors, NusG/Spt5 stand out as the only universally conserved family of regulators. These proteins interact with RNAP to promote uninterrupted RNA synthesis and with diverse cellular partners to couple transcription to RNA processing, modification or translation, or to trigger premature termination of aberrant transcription. NusG homologs are present in all cells that utilize bacterial-type RNAP, from endosymbionts to plants, underscoring their ancient and essential function. Yet, in stark contrast to other core RNAP components, NusG family is actively evolving: horizontal gene transfer and sub-functionalization drive emergence of NusG paralogs, such as bacterial LoaP, RfaH, and UpxY. These specialized regulators activate a few (or just one) operons required for expression of antibiotics, capsules, secretion systems, toxins, and other niche-specific macromolecules. Despite their common origin and binding site on the RNAP, NusG homologs differ in their target selection, interacting partners and effects on RNA synthesis. Even among housekeeping NusGs from diverse bacteria, some factors promote pause-free transcription while others slow the RNAP down. Here, we discuss structure, function, and evolution of NusG proteins, focusing on unique mechanisms that determine their effects on gene expression and enable bacterial adaptation to diverse ecological niches.
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Affiliation(s)
- Bing Wang
- Department of Microbiology and the Center for RNA Biology, The Ohio State University, Columbus, OH, United States
| | - Irina Artsimovitch
- Department of Microbiology and the Center for RNA Biology, The Ohio State University, Columbus, OH, United States
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