1
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Chen X, Qi Y, Wu Z, Wang X, Li J, Zhao D, Hou H, Li Y, Yu Z, Liu W, Wang M, Ren Y, Li Z, Yang H, Xu Y. Structural insights into preinitiation complex assembly on core promoters. Science 2021; 372:science.aba8490. [PMID: 33795473 DOI: 10.1126/science.aba8490] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 02/01/2021] [Accepted: 03/25/2021] [Indexed: 12/24/2022]
Abstract
Transcription factor IID (TFIID) recognizes core promoters and supports preinitiation complex (PIC) assembly for RNA polymerase II (Pol II)-mediated eukaryotic transcription. We determined the structures of human TFIID-based PIC in three stepwise assembly states and revealed two-track PIC assembly: stepwise promoter deposition to Pol II and extensive modular reorganization on track I (on TATA-TFIID-binding element promoters) versus direct promoter deposition on track II (on TATA-only and TATA-less promoters). The two tracks converge at an ~50-subunit holo PIC in identical conformation, whereby TFIID stabilizes PIC organization and supports loading of cyclin-dependent kinase (CDK)-activating kinase (CAK) onto Pol II and CAK-mediated phosphorylation of the Pol II carboxyl-terminal domain. Unexpectedly, TBP of TFIID similarly bends TATA box and TATA-less promoters in PIC. Our study provides structural visualization of stepwise PIC assembly on highly diversified promoters.
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Affiliation(s)
- Xizi Chen
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yilun Qi
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zihan Wu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinxin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiabei Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Dan Zhao
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Haifeng Hou
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yan Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zishuo Yu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Weida Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Mo Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yulei Ren
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Ze Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Huirong Yang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China. .,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China.,Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China
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2
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Direct binding of TFEα opens DNA binding cleft of RNA polymerase. Nat Commun 2020; 11:6123. [PMID: 33257704 PMCID: PMC7704642 DOI: 10.1038/s41467-020-19998-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/29/2020] [Indexed: 01/09/2023] Open
Abstract
Opening of the DNA binding cleft of cellular RNA polymerase (RNAP) is necessary for transcription initiation but the underlying molecular mechanism is not known. Here, we report on the cryo-electron microscopy structures of the RNAP, RNAP-TFEα binary, and RNAP-TFEα-promoter DNA ternary complexes from archaea, Thermococcus kodakarensis (Tko). The structures reveal that TFEα bridges the RNAP clamp and stalk domains to open the DNA binding cleft. Positioning of promoter DNA into the cleft closes it while maintaining the TFEα interactions with the RNAP mobile modules. The structures and photo-crosslinking results also suggest that the conserved aromatic residue in the extended winged-helix domain of TFEα interacts with promoter DNA to stabilize the transcription bubble. This study provides a structural basis for the functions of TFEα and elucidates the mechanism by which the DNA binding cleft is opened during transcription initiation in the stalk-containing RNAPs, including archaeal and eukaryotic RNAPs.
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3
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Modulation of androgen receptor DNA binding activity through direct interaction with the ETS transcription factor ERG. Proc Natl Acad Sci U S A 2020; 117:8584-8592. [PMID: 32220959 PMCID: PMC7165421 DOI: 10.1073/pnas.1922159117] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Progress in studying the androgen receptor (AR), the primary drug target in prostate cancer, has been hampered by challenges in expressing and purifying active multidomain AR for use in cell-free biochemical reconstitution assays. Here we successfully express full-length and truncated AR variants and demonstrate that the oncogenic ETS protein ERG, responsible for half of all prostate cancers, enhances the ability of AR to bind DNA through direct interaction with AR. In addition to providing a biochemical system to evaluate AR activity on different DNA templates, our findings provide insight into why ERG-positive prostate cancers have an expanded AR cistrome. The androgen receptor (AR) is a type I nuclear hormone receptor and the primary drug target in prostate cancer due to its role as a lineage survival factor in prostate luminal epithelium. In prostate cancer, the AR cistrome is reprogrammed relative to normal prostate epithelium and particularly in cancers driven by oncogenic ETS fusion genes. The molecular basis for this change has remained elusive. Using purified proteins, we report a minimal cell-free system that demonstrates interdomain cooperativity between the ligand (LBD) and DNA binding domains (DBD) of AR, and its autoinhibition by the N terminus of AR. Furthermore, we identify ERG as a cofactor that activates AR’s ability to bind DNA in both high and lower affinity contexts through direct interaction within a newly identified AR-interacting motif (AIM) in the ETS domain, independent of ERG’s own DNA binding ability. Finally, we present evidence that this interaction is conserved among ETS factors whose expression is altered in prostate cancer. Our work highlights, at a biochemical level, how tumor-initiating ETS translocations result in reprogramming of the AR cistrome.
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4
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Ayoubi LE, Dumay-Odelot H, Chernev A, Boissier F, Minvielle-Sébastia L, Urlaub H, Fribourg S, Teichmann M. The hRPC62 subunit of human RNA polymerase III displays helicase activity. Nucleic Acids Res 2019; 47:10313-10326. [PMID: 31529052 PMCID: PMC6821166 DOI: 10.1093/nar/gkz788] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 08/30/2019] [Accepted: 09/12/2019] [Indexed: 11/20/2022] Open
Abstract
In Eukaryotes, tRNAs, 5S RNA and U6 RNA are transcribed by RNA polymerase (Pol) III. Human Pol III is composed of 17 subunits. Three specific Pol III subunits form a stable ternary subcomplex (RPC62-RPC39-RPC32α/β) being involved in pre-initiation complex formation. No paralogues for subunits of this subcomplex subunits have been found in Pols I or II, but hRPC62 was shown to be structurally related to the general Pol II transcription factor hTFIIEα. Here we show that these structural homologies extend to functional similarities. hRPC62 as well as hTFIIEα possess intrinsic ATP-dependent 3′-5′ DNA unwinding activity. The ATPase activities of both proteins are stimulated by single-stranded DNA. Moreover, the eWH domain of hTFIIEα can replace the first eWH (eWH1) domain of hRPC62 in ATPase and DNA unwinding assays. Our results identify intrinsic enzymatic activities in hRPC62 and hTFIIEα.
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Affiliation(s)
- Leyla El Ayoubi
- ARNA Laboratory, Inserm U1212, CNRS UMR 5320, Université de Bordeaux, 33000 Bordeaux, France
| | - Hélène Dumay-Odelot
- ARNA Laboratory, Inserm U1212, CNRS UMR 5320, Université de Bordeaux, 33000 Bordeaux, France
- Correspondence may also be addressed to Hélène Dumay-Odelot.
| | - Aleksandar Chernev
- Max Planck Institute for Biophysical Chemistry, Research group Mass Spectrometry, Am Faßberg 11, 37077 Göttingen, Germany
| | - Fanny Boissier
- ARNA Laboratory, Inserm U1212, CNRS UMR 5320, Université de Bordeaux, 33000 Bordeaux, France
| | | | - Henning Urlaub
- Max Planck Institute for Biophysical Chemistry, Research group Mass Spectrometry, Am Faßberg 11, 37077 Göttingen, Germany
- Bioanalytics, Institute for Clinical Chemistry, University Medical Center, Robert-Koch-Strasse 420, 37075 Göttingen, Germany
| | - Sébastien Fribourg
- ARNA Laboratory, Inserm U1212, CNRS UMR 5320, Université de Bordeaux, 33000 Bordeaux, France
| | - Martin Teichmann
- ARNA Laboratory, Inserm U1212, CNRS UMR 5320, Université de Bordeaux, 33000 Bordeaux, France
- To whom correspondence should be addressed. Tel: +33 5 5757 4647;
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5
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Khoo SK, Wu CC, Lin YC, Chen HT. The TFIIE-related Rpc82 subunit of RNA polymerase III interacts with the TFIIB-related transcription factor Brf1 and the polymerase cleft for transcription initiation. Nucleic Acids Res 2019; 46:1157-1166. [PMID: 29177422 PMCID: PMC5814912 DOI: 10.1093/nar/gkx1179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 11/16/2017] [Indexed: 11/13/2022] Open
Abstract
Rpc82 is a TFIIE-related subunit of the eukaryotic RNA polymerase III (pol III) complex. Rpc82 contains four winged-helix (WH) domains and a C-terminal coiled-coil domain. Structural resolution of the pol III complex indicated that Rpc82 anchors on the clamp domain of the pol III cleft to interact with the duplex DNA downstream of the transcription bubble. However, whether Rpc82 interacts with a transcription factor is still not known. Here, we report that a structurally disordered insertion in the third WH domain of Rpc82 is important for cell growth and in vitro transcription activity. Site-specific photo-crosslinking analysis indicated that the WH3 insertion interacts with the TFIIB-related transcription factor Brf1 within the pre-initiation complex (PIC). Moreover, crosslinking and hydroxyl radical probing analyses revealed Rpc82 interactions with the upstream DNA and the protrusion and wall domains of the pol III cleft. Our genetic and biochemical analyses thus provide new molecular insights into the function of Rpc82 in pol III transcription.
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Affiliation(s)
- Seok-Kooi Khoo
- Institute of Molecular Biology, Academia Sinica, 128 Sec. 2 Academia Rd., Taipei 115, Taiwan, R.O.C
| | - Chih-Chien Wu
- Institute of Molecular Biology, Academia Sinica, 128 Sec. 2 Academia Rd., Taipei 115, Taiwan, R.O.C
| | - Yu-Chun Lin
- Institute of Molecular Biology, Academia Sinica, 128 Sec. 2 Academia Rd., Taipei 115, Taiwan, R.O.C
| | - Hung-Ta Chen
- Institute of Molecular Biology, Academia Sinica, 128 Sec. 2 Academia Rd., Taipei 115, Taiwan, R.O.C
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6
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Blombach F, Matelska D, Fouqueau T, Cackett G, Werner F. Key Concepts and Challenges in Archaeal Transcription. J Mol Biol 2019; 431:4184-4201. [PMID: 31260691 DOI: 10.1016/j.jmb.2019.06.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 12/17/2022]
Abstract
Transcription is enabled by RNA polymerase and general factors that allow its progress through the transcription cycle by facilitating initiation, elongation and termination. The transitions between specific stages of the transcription cycle provide opportunities for the global and gene-specific regulation of gene expression. The exact mechanisms and the extent to which the different steps of transcription are exploited for regulation vary between the domains of life, individual species and transcription units. However, a surprising degree of conservation is apparent. Similar key steps in the transcription cycle can be targeted by homologous or unrelated factors providing insights into the mechanisms of RNAP and the evolution of the transcription machinery. Archaea are bona fide prokaryotes but employ a eukaryote-like transcription system to express the information of bacteria-like genomes. Thus, archaea provide the means not only to study transcription mechanisms of interesting model systems but also to test key concepts of regulation in this arena. In this review, we discuss key principles of archaeal transcription, new questions that still await experimental investigation, and how novel integrative approaches hold great promise to fill this gap in our knowledge.
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Affiliation(s)
- Fabian Blombach
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
| | - Dorota Matelska
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Thomas Fouqueau
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Gwenny Cackett
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Finn Werner
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
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7
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Abstract
In all living organisms, the flow of genetic information is a two-step process: first DNA is transcribed into RNA, which is subsequently used as template for protein synthesis during translation. In bacteria, archaea and eukaryotes, transcription is carried out by multi-subunit RNA polymerases (RNAPs) sharing a conserved architecture of the RNAP core. RNAPs catalyse the highly accurate polymerisation of RNA from NTP building blocks, utilising DNA as template, being assisted by transcription factors during the initiation, elongation and termination phase of transcription. The complexity of this highly dynamic process is reflected in the intricate network of protein-protein and protein-nucleic acid interactions in transcription complexes and the substantial conformational changes of the RNAP as it progresses through the transcription cycle.In this chapter, we will first briefly describe the early work that led to the discovery of multisubunit RNAPs. We will then discuss the three-dimensional organisation of RNAPs from the bacterial, archaeal and eukaryotic domains of life, highlighting the conserved nature, but also the domain-specific features of the transcriptional apparatus. Another section will focus on transcription factors and their role in regulating the RNA polymerase throughout the different phases of the transcription cycle. This includes a discussion of the molecular mechanisms and dynamic events that govern transcription initiation, elongation and termination.
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8
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Blombach F, Ausiannikava D, Figueiredo A, Soloviev Z, Prentice T, Zhang M, Zhou N, Thalassinos K, Allers T, Werner F. Structural and functional adaptation of Haloferax volcanii TFEα/β. Nucleic Acids Res 2018; 46:2308-2320. [PMID: 29309690 PMCID: PMC5861453 DOI: 10.1093/nar/gkx1302] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 12/08/2017] [Accepted: 12/19/2017] [Indexed: 12/14/2022] Open
Abstract
The basal transcription factor TFE enhances transcription initiation by catalysing DNA strand-separation, a process that varies with temperature and ionic strength. Canonical TFE forms a heterodimeric complex whose integrity and function critically relies on a cubane iron-sulphur cluster residing in the TFEβ subunit. Halophilic archaea such as Haloferax volcanii have highly divergent putative TFEβ homologues with unknown properties. Here, we demonstrate that Haloferax TFEβ lacks the prototypical iron-sulphur cluster yet still forms a stable complex with TFEα. A second metal cluster contained in the zinc ribbon domain in TFEα is highly degenerate but retains low binding affinity for zinc, which contributes to protein folding and stability. The deletion of the tfeB gene in H. volcanii results in the aberrant expression of approximately one third of all genes, consistent with its function as a basal transcription initiation factor. Interestingly, tfeB deletion particularly affects foreign genes including a prophage region. Our results reveal the loss of metal centres in Hvo transcription factors, and confirm the dual function of TFE as basal factor and regulator of transcription.
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Affiliation(s)
- Fabian Blombach
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Darya Ausiannikava
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Angelo Miguel Figueiredo
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Zoja Soloviev
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Tanya Prentice
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Mark Zhang
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Nanruoyi Zhou
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Konstantinos Thalassinos
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
| | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Finn Werner
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, UK
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9
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Li YC, Naveen V, Lin MG, Hsiao CD. Structural analyses of the bacterial primosomal protein DnaB reveal that it is a tetramer and forms a complex with a primosomal re-initiation protein. J Biol Chem 2017; 292:15744-15757. [PMID: 28808061 PMCID: PMC5612107 DOI: 10.1074/jbc.m117.792002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 08/08/2017] [Indexed: 11/06/2022] Open
Abstract
The DnaB primosomal protein from Gram-positive bacteria plays a key role in DNA replication and restart as a loader protein for the recruitment of replisome cascade proteins. Previous investigations have established that DnaB is composed of an N-terminal domain, a middle domain, and a C-terminal domain. However, structural evidence for how DnaB functions at the atomic level is lacking. Here, we report the crystal structure of DnaB, encompassing the N-terminal and middle domains (residues 1-300), from Geobacillus stearothermophilus (GstDnaB1-300) at 2.8 Å resolution. Our structure revealed that GstDnaB1-300 forms a tetramer with two basket-like architectures, a finding consistent with those from solution studies using analytical ultracentrifugation. Furthermore, our results from both GST pulldown assays and analytical ultracentrifugation show that GstDnaB1-300 is sufficient to form a complex with PriA, the primosomal reinitiation protein. Moreover, with the aid of small angle X-ray scattering experiments, we also determined the structural envelope of full-length DnaB (GstDnaBFL) in solution. These small angle X-ray scattering studies indicated that GstDnaBFL has an elongated conformation and that the protruding density envelopes originating from GstDnaB1-300 could completely accommodate the GstDnaB C-terminal domain (residues 301-461). Taken together with biochemical assays, our results suggest that GstDnaB uses different domains to distinguish the PriA interaction and single-stranded DNA binding. These findings can further extend our understanding of primosomal assembly in replication restart.
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Affiliation(s)
- Yi-Ching Li
- From the Institute of Molecular Biology, Academia Sinica, Taipei, 115, Taiwan and
| | - Vankadari Naveen
- From the Institute of Molecular Biology, Academia Sinica, Taipei, 115, Taiwan and
| | - Min-Guan Lin
- From the Institute of Molecular Biology, Academia Sinica, Taipei, 115, Taiwan and
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Chwan-Deng Hsiao
- From the Institute of Molecular Biology, Academia Sinica, Taipei, 115, Taiwan and
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10
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Cramer P. Structural Molecular Biology-A Personal Reflection on the Occasion of John Kendrew's 100th Birthday. J Mol Biol 2017; 429:2603-2610. [PMID: 28501586 DOI: 10.1016/j.jmb.2017.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 10/19/2022]
Abstract
Here, I discuss the development and future of structural molecular biology, concentrating on the eukaryotic transcription machinery and reflecting on John Kendrew's legacy from a personal perspective.
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Affiliation(s)
- Patrick Cramer
- Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany.
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11
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Hantsche M, Cramer P. Strukturelle Grundlage der Transkription: 10 Jahre nach dem Chemie-Nobelpreis. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Merle Hantsche
- Abteilung für Molekularbiologie; Max-Planck-Institut für biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Deutschland
| | - Patrick Cramer
- Abteilung für Molekularbiologie; Max-Planck-Institut für biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Deutschland
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12
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Hantsche M, Cramer P. The Structural Basis of Transcription: 10 Years After the Nobel Prize in Chemistry. Angew Chem Int Ed Engl 2016; 55:15972-15981. [DOI: 10.1002/anie.201608066] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Indexed: 12/21/2022]
Affiliation(s)
- Merle Hantsche
- Abteilung für Molekularbiologie; Max Planck Institut für biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Germany
| | - Patrick Cramer
- Abteilung für Molekularbiologie; Max Planck Institut für biophysikalische Chemie; Am Fassberg 11 37077 Göttingen Germany
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13
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Yi X, Dean AM. Phenotypic plasticity as an adaptation to a functional trade-off. eLife 2016; 5. [PMID: 27692064 PMCID: PMC5072838 DOI: 10.7554/elife.19307] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 09/28/2016] [Indexed: 01/05/2023] Open
Abstract
We report the evolution of a phenotypically plastic behavior that circumvents the hardwired trade-off that exists when resources are partitioned between growth and motility in Escherichia coli. We propagated cultures in a cyclical environment, alternating between growth up to carrying capacity and selection for chemotaxis. Initial adaptations boosted overall swimming speed at the expense of growth. The effect of the trade-off was subsequently eased through a change in behavior; while individual cells reduced motility during exponential growth, the faction of the population that was motile increased as the carrying capacity was approached. This plastic behavior was produced by a single amino acid replacement in FliA, a regulatory protein central to the chemotaxis network. Our results illustrate how phenotypic plasticity potentiates evolvability by opening up new regions of the adaptive landscape. DOI:http://dx.doi.org/10.7554/eLife.19307.001
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Affiliation(s)
- Xiao Yi
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, United States
| | - Antony M Dean
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, United States.,Laboratory of Microbial Evolution, College of Ecology and Evolution, Guangzhou, Peoples Republic of China
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14
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Miwa K, Kojima R, Obita T, Ohkuma Y, Tamura Y, Mizuguchi M. Crystal Structure of Human General Transcription Factor TFIIE at Atomic Resolution. J Mol Biol 2016; 428:4258-4266. [DOI: 10.1016/j.jmb.2016.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 09/09/2016] [Accepted: 09/09/2016] [Indexed: 11/17/2022]
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15
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Abstract
The known diversity of metabolic strategies and physiological adaptations of archaeal species to extreme environments is extraordinary. Accurate and responsive mechanisms to ensure that gene expression patterns match the needs of the cell necessitate regulatory strategies that control the activities and output of the archaeal transcription apparatus. Archaea are reliant on a single RNA polymerase for all transcription, and many of the known regulatory mechanisms employed for archaeal transcription mimic strategies also employed for eukaryotic and bacterial species. Novel mechanisms of transcription regulation have become apparent by increasingly sophisticated in vivo and in vitro investigations of archaeal species. This review emphasizes recent progress in understanding archaeal transcription regulatory mechanisms and highlights insights gained from studies of the influence of archaeal chromatin on transcription.
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16
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Plaschka C, Hantsche M, Dienemann C, Burzinski C, Plitzko J, Cramer P. Transcription initiation complex structures elucidate DNA opening. Nature 2016; 533:353-8. [DOI: 10.1038/nature17990] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/08/2016] [Indexed: 12/19/2022]
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17
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He Y, Yan C, Fang J, Inouye C, Tjian R, Ivanov I, Nogales E. Near-atomic resolution visualization of human transcription promoter opening. Nature 2016; 533:359-65. [PMID: 27193682 PMCID: PMC4940141 DOI: 10.1038/nature17970] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/05/2016] [Indexed: 12/11/2022]
Abstract
In eukaryotic transcription initiation, a large multi-subunit pre-initiation complex (PIC) that assembles at the core promoter is required for the opening of the duplex DNA and identification of the start site for transcription by RNA polymerase II. Here we use cryo-electron microscropy (cryo-EM) to determine near-atomic resolution structures of the human PIC in a closed state (engaged with duplex DNA), an open state (engaged with a transcription bubble), and an initially transcribing complex (containing six base pairs of DNA-RNA hybrid). Our studies provide structures for previously uncharacterized components of the PIC, such as TFIIE and TFIIH, and segments of TFIIA, TFIIB and TFIIF. Comparison of the different structures reveals the sequential conformational changes that accompany the transition from each state to the next throughout the transcription initiation process. This analysis illustrates the key role of TFIIB in transcription bubble stabilization and provides strong structural support for a translocase activity of XPB.
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Affiliation(s)
- Yuan He
- Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA
| | - Chunli Yan
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia 30302, USA
| | - Jie Fang
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA
| | - Carla Inouye
- Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, California 94720, USA
| | - Robert Tjian
- Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA.,Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, California 94720, USA.,Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
| | - Ivaylo Ivanov
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia 30302, USA
| | - Eva Nogales
- Molecular Biophysics and Integrative Bio-Imaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, California 94720, USA.,Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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18
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Molecular Mechanisms of Transcription Initiation-Structure, Function, and Evolution of TFE/TFIIE-Like Factors and Open Complex Formation. J Mol Biol 2016; 428:2592-2606. [PMID: 27107643 DOI: 10.1016/j.jmb.2016.04.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/06/2016] [Accepted: 04/12/2016] [Indexed: 11/24/2022]
Abstract
Transcription initiation requires that the promoter DNA is melted and the template strand is loaded into the active site of the RNA polymerase (RNAP), forming the open complex (OC). The archaeal initiation factor TFE and its eukaryotic counterpart TFIIE facilitate this process. Recent structural and biophysical studies have revealed the position of TFE/TFIIE within the pre-initiation complex (PIC) and illuminated its role in OC formation. TFE operates via allosteric and direct mechanisms. Firstly, it interacts with the RNAP and induces the opening of the flexible RNAP clamp domain, concomitant with DNA melting and template loading. Secondly, TFE binds physically to single-stranded DNA in the transcription bubble of the OC and increases its stability. The identification of the β-subunit of archaeal TFE enabled us to reconstruct the evolutionary history of TFE/TFIIE-like factors, which is characterised by winged helix (WH) domain expansion in eukaryotes and loss of metal centres including iron-sulfur clusters and Zinc ribbons. OC formation is an important target for the regulation of transcription in all domains of life. We propose that TFE and the bacterial general transcription factor CarD, although structurally and evolutionary unrelated, show interesting parallels in their mechanism to enhance OC formation. We argue that OC formation is used as a way to regulate transcription in all domains of life, and these regulatory mechanisms coevolved with the basal transcription machinery.
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19
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Abstract
The structure of a 33-protein, 1.5-MDa RNA polymerase II preinitiation complex (PIC) was determined by cryo-EM and image processing at a resolution of 6-11 Å. Atomic structures of over 50% of the mass were fitted into the electron density map in a manner consistent with protein-protein cross-links previously identified by mass spectrometry. The resulting model of the PIC confirmed the main conclusions from previous cryo-EM at lower resolution, including the association of promoter DNA only with general transcription factors and not with the polymerase. Electron density due to DNA was identifiable by the grooves of the double helix and exhibited sharp bends at points downstream of the TATA box, with an important consequence: The DNA at the downstream end coincides with the DNA in a transcribing polymerase. The structure of the PIC is therefore conducive to promoter melting, start-site scanning, and the initiation of transcription.
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20
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Ahmad MUD, Waege I, Hausner W, Thomm M, Boos W, Diederichs K, Welte W. Structural Insights into Nonspecific Binding of DNA by TrmBL2, an Archaeal Chromatin Protein. J Mol Biol 2015; 427:3216-3229. [PMID: 26299937 DOI: 10.1016/j.jmb.2015.08.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/04/2015] [Accepted: 08/10/2015] [Indexed: 10/23/2022]
Abstract
The crystal structure of TrmBL2 from the archaeon Pyrococcus furiosus shows an association of two pseudosymmetric dimers. The dimers follow the prototypical design of known bacterial repressors with two helix-turn-helix (HTH) domains binding to successive major grooves of the DNA. However, in TrmBL2, the two dimers are arranged at a mutual displacement of approximately 2bp so that they associate with the DNA along the double-helical axis at an angle of approximately 80°. While the deoxyribose phosphate groups of the double-stranded DNA (dsDNA) used for co-crystallization are clearly seen in the electron density map, most of the nucleobases are averaged out. Refinement required to assume a superposition of at least three mutually displaced dsDNAs. The HTH domains interact primarily with the deoxyribose phosphate groups and polar interactions with the nucleobases are almost absent. This hitherto unseen mode of DNA binding by TrmBL2 seems to arise from nonoptimal protein-DNA contacts made by its four HTH domains resulting in a low-affinity, nonspecific binding to DNA.
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Affiliation(s)
- Misbha Ud Din Ahmad
- University of Konstanz Department of Biology, Universitätsstrasse 10, 78456 Konstanz, Germany
| | - Ingrid Waege
- University Regensburg Lehrstuhl für Mikrobiologie, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Winfried Hausner
- University Regensburg Lehrstuhl für Mikrobiologie, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Michael Thomm
- University Regensburg Lehrstuhl für Mikrobiologie, Universitätsstrasse 31, 93053 Regensburg, Germany
| | - Winfried Boos
- University of Konstanz Department of Biology, Universitätsstrasse 10, 78456 Konstanz, Germany
| | - Kay Diederichs
- University of Konstanz Department of Biology, Universitätsstrasse 10, 78456 Konstanz, Germany
| | - Wolfram Welte
- University of Konstanz Department of Biology, Universitätsstrasse 10, 78456 Konstanz, Germany.
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21
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Blombach F, Salvadori E, Fouqueau T, Yan J, Reimann J, Sheppard C, Smollett KL, Albers SV, Kay CWM, Thalassinos K, Werner F. Archaeal TFEα/β is a hybrid of TFIIE and the RNA polymerase III subcomplex hRPC62/39. eLife 2015; 4:e08378. [PMID: 26067235 PMCID: PMC4495717 DOI: 10.7554/elife.08378] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 06/11/2015] [Indexed: 01/01/2023] Open
Abstract
Transcription initiation of archaeal RNA polymerase (RNAP) and eukaryotic RNAPII is assisted by conserved basal transcription factors. The eukaryotic transcription factor TFIIE consists of α and β subunits. Here we have identified and characterised the function of the TFIIEβ homologue in archaea that on the primary sequence level is related to the RNAPIII subunit hRPC39. Both archaeal TFEβ and hRPC39 harbour a cubane 4Fe-4S cluster, which is crucial for heterodimerization of TFEα/β and its engagement with the RNAP clamp. TFEα/β stabilises the preinitiation complex, enhances DNA melting, and stimulates abortive and productive transcription. These activities are strictly dependent on the β subunit and the promoter sequence. Our results suggest that archaeal TFEα/β is likely to represent the evolutionary ancestor of TFIIE-like factors in extant eukaryotes.
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Affiliation(s)
- Fabian Blombach
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Enrico Salvadori
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
- London Centre for Nanotechnology, University College London, London, United Kingdom
| | - Thomas Fouqueau
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Jun Yan
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Julia Reimann
- Molecular Biology of Archaea Group, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Carol Sheppard
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Katherine L Smollett
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Sonja V Albers
- Molecular Biology of Archaea Group, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- Microbiology, University of Freiburg, Freiburg, Germany
| | - Christopher WM Kay
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
- London Centre for Nanotechnology, University College London, London, United Kingdom
| | - Konstantinos Thalassinos
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
| | - Finn Werner
- Institute for Structural and Molecular Biology, Division of Biosciences, University College London, London, United Kingdom
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22
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Architecture of TFIIIC and its role in RNA polymerase III pre-initiation complex assembly. Nat Commun 2015; 6:7387. [PMID: 26060179 PMCID: PMC4490372 DOI: 10.1038/ncomms8387] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/04/2015] [Indexed: 02/05/2023] Open
Abstract
In eukaryotes, RNA Polymerase III (Pol III) is specifically responsible for transcribing genes encoding tRNAs and other short non-coding RNAs. The recruitment of Pol III to tRNA-encoding genes requires the transcription factors (TF) IIIB and IIIC. TFIIIC has been described as a conserved, multi-subunit protein complex composed of two subcomplexes, called τA and τB. How these two subcomplexes are linked and how their interaction affects the formation of the Pol III pre-initiation complex (PIC) is poorly understood. Here we use chemical crosslinking mass spectrometry and determine the molecular architecture of TFIIIC. We further report the crystal structure of the essential TPR array from τA subunit τ131 and characterize its interaction with a central region of τB subunit τ138. The identified τ131–τ138 interacting region is essential in vivo and overlaps with TFIIIB-binding sites, revealing a crucial interaction platform for the regulation of tRNA transcription initiation. TFIIIC is a RNA polymerase III-specific general transcription factor complex essential for tRNA synthesis. Here the authors combine chemical crosslinking/mass spectrometry and X-ray crystallography to define the architecture of TFIIIC and suggest a model for the assembly of pre-initiation complexes at tRNA genes.
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23
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Abstract
Transcription of eukaryotic protein-coding genes commences with the assembly of a conserved initiation complex, which consists of RNA polymerase II (Pol II) and the general transcription factors, at promoter DNA. After two decades of research, the structural basis of transcription initiation is emerging. Crystal structures of many components of the initiation complex have been resolved, and structural information on Pol II complexes with general transcription factors has recently been obtained. Although mechanistic details await elucidation, available data outline how Pol II cooperates with the general transcription factors to bind to and open promoter DNA, and how Pol II directs RNA synthesis and escapes from the promoter.
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24
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Tanaka A, Akimoto Y, Kobayashi S, Hisatake K, Hanaoka F, Ohkuma Y. Association of the winged helix motif of the TFIIEα subunit of TFIIE with either the TFIIEβ subunit or TFIIB distinguishes its functions in transcription. Genes Cells 2014; 20:203-16. [PMID: 25492609 DOI: 10.1111/gtc.12212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/10/2014] [Indexed: 01/23/2023]
Abstract
In eukaryotes, the general transcription factor TFIIE consists of two subunits, α and β, and plays essential roles in transcription. Structure-function studies indicate that TFIIE has three-winged helix (WH) motifs, with one in TFIIEα and two in TFIIEβ. Recent studies suggested that, by binding to the clamp region of RNA polymerase II, TFIIEα-WH promotes the conformational change that transforms the promoter-bound inactive preinitiation complex to the active complex. Here, to elucidate its roles in transcription, functional analyses of point-mutated human TFIIEα-WH proteins were carried out. In vitro transcription analyses identified two classes of mutants. One class was defective in transcription initiation, and the other was defective in the transition from initiation to elongation. Analyses of the binding of this motif to other general transcription factors showed that the former class was defective in binding to the basic helix-loop-helix motif of TFIIEβ and the latter class was defective in binding to the N-terminal cyclin homology region of TFIIB. Furthermore, TFIIEα-WH bound to the TFIIH XPB subunit at a third distinct region. Therefore, these results provide further insights into the mechanisms underlying RNA polymerase II activation at the initial stages of transcription.
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Affiliation(s)
- Aki Tanaka
- Laboratory of Gene Regulation, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
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25
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26
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RNA polymerase III subunit architecture and implications for open promoter complex formation. Proc Natl Acad Sci U S A 2012; 109:19232-7. [PMID: 23132938 DOI: 10.1073/pnas.1211665109] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Transcription initiation by eukaryotic RNA polymerase (Pol) III relies on the TFIIE-related subcomplex C82/34/31. Here we combine cross-linking and hydroxyl radical probing to position the C82/34/31 subcomplex around the Pol III active center cleft. The extended winged helix (WH) domains 1 and 4 of C82 localize to the polymerase domains clamp head and clamp core, respectively, and the two WH domains of C34 span the polymerase cleft from the coiled-coil region of the clamp to the protrusion. The WH domains of C82 and C34 apparently cooperate with other mobile regions flanking the cleft during promoter DNA binding, opening, and loading. Together with published data, our results complete the subunit architecture of Pol III and indicate that all TFIIE-related components of eukaryotic and archaeal transcription systems adopt an evolutionarily conserved location in the upper part of the cleft that supports their functions in open promoter complex formation and stabilization.
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27
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Sousounis K, Haney CE, Cao J, Sunchu B, Tsonis PA. Conservation of the three-dimensional structure in non-homologous or unrelated proteins. Hum Genomics 2012; 6:10. [PMID: 23244440 PMCID: PMC3500211 DOI: 10.1186/1479-7364-6-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 05/14/2012] [Indexed: 12/12/2022] Open
Abstract
In this review, we examine examples of conservation of protein structural motifs in unrelated or non-homologous proteins. For this, we have selected three DNA-binding motifs: the histone fold, the helix-turn-helix motif, and the zinc finger, as well as the globin-like fold. We show that indeed similar structures exist in unrelated proteins, strengthening the concept that three-dimensional conservation might be more important than the primary amino acid sequence.
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28
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Grünberg S, Warfield L, Hahn S. Architecture of the RNA polymerase II preinitiation complex and mechanism of ATP-dependent promoter opening. Nat Struct Mol Biol 2012; 19:788-96. [PMID: 22751016 PMCID: PMC3414687 DOI: 10.1038/nsmb.2334] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 05/28/2012] [Indexed: 01/23/2023]
Abstract
Yeast RNA polymerase (Pol) II general factor TFIIE and the TFIIH subunit Ssl2/XPB function in transition of the preinitiation complex (PIC) to the open complex. We find that the three TFIIE winged helix (WH) domains form a heterodimer, with the Tfa1/TFIIEα WH binding the Pol II clamp and the Tfa2/TFIIEβ tandem WH domain encircling promoter DNA that becomes single stranded in the open complex. Ssl2 lies adjacent to TFIIE, enclosing downstream promoter DNA. In contrast to previous proposals, comparison of the PIC and open complex models strongly suggests that Ssl2 promotes DNA opening by functioning as a double stranded DNA translocase, feeding 15 bp of double stranded DNA into the Pol II cleft. Right-handed threading of DNA through the Ssl2 binding groove, combined with the fixed position of upstream promoter DNA, will lead to DNA unwinding and the open state.
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29
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Teichmann M, Dumay-Odelot H, Fribourg S. Structural and functional aspects of winged-helix domains at the core of transcription initiation complexes. Transcription 2012; 3:2-7. [PMID: 22456313 DOI: 10.4161/trns.3.1.18917] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The winged helix (WH) domain is found in core components of transcription systems in eukaryotes and prokaryotes. It represents a sub-class of the helix-turn-helix motif. The WH domain participates in establishing protein-DNA and protein-protein-interactions. Here, we discuss possible explanations for the enrichment of this motif in transcription systems.
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Affiliation(s)
- Martin Teichmann
- Université de Bordeaux, Institut Européen de Chimie et Biologie, Pessac, France
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30
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Vannini A, Cramer P. Conservation between the RNA polymerase I, II, and III transcription initiation machineries. Mol Cell 2012; 45:439-46. [PMID: 22365827 DOI: 10.1016/j.molcel.2012.01.023] [Citation(s) in RCA: 305] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/25/2012] [Accepted: 01/30/2012] [Indexed: 01/24/2023]
Abstract
Recent studies of the three eukaryotic transcription machineries revealed that all initiation complexes share a conserved core. This core consists of the RNA polymerase (I, II, or III), the TATA box-binding protein (TBP), and transcription factors TFIIB, TFIIE, and TFIIF (for Pol II) or proteins structurally and functionally related to parts of these factors (for Pol I and Pol III). The conserved core initiation complex stabilizes the open DNA promoter complex and directs initial RNA synthesis. The periphery of the core initiation complex is decorated by additional polymerase-specific factors that account for functional differences in promoter recognition and opening, and gene class-specific regulation. This review outlines the similarities and differences between these important molecular machines.
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Affiliation(s)
- Alessandro Vannini
- Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
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31
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Grohmann D, Nagy J, Chakraborty A, Klose D, Fielden D, Ebright RH, Michaelis J, Werner F. The initiation factor TFE and the elongation factor Spt4/5 compete for the RNAP clamp during transcription initiation and elongation. Mol Cell 2012; 43:263-74. [PMID: 21777815 PMCID: PMC3223566 DOI: 10.1016/j.molcel.2011.05.030] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/09/2011] [Accepted: 05/24/2011] [Indexed: 01/24/2023]
Abstract
TFIIE and the archaeal homolog TFE enhance DNA strand separation of eukaryotic RNAPII and the archaeal RNAP during transcription initiation by an unknown mechanism. We have developed a fluorescently labeled recombinant M. jannaschii RNAP system to probe the archaeal transcription initiation complex, consisting of promoter DNA, TBP, TFB, TFE, and RNAP. We have localized the position of the TFE winged helix (WH) and Zinc ribbon (ZR) domains on the RNAP using single-molecule FRET. The interaction sites of the TFE WH domain and the transcription elongation factor Spt4/5 overlap, and both factors compete for RNAP binding. Binding of Spt4/5 to RNAP represses promoter-directed transcription in the absence of TFE, which alleviates this effect by displacing Spt4/5 from RNAP. During elongation, Spt4/5 can displace TFE from the RNAP elongation complex and stimulate processivity. Our results identify the RNAP “clamp” region as a regulatory hot spot for both transcription initiation and transcription elongation.
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Affiliation(s)
- Dina Grohmann
- University College London, Institute for Structural and Molecular Biology, Division of Biosciences, Darwin Building, Gower Street, London WC1E 6BT, UK
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32
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Luo J, Fishburn J, Hahn S, Ranish J. An integrated chemical cross-linking and mass spectrometry approach to study protein complex architecture and function. Mol Cell Proteomics 2011; 11:M111.008318. [PMID: 22067100 DOI: 10.1074/mcp.m111.008318] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Knowledge of protein structures and protein-protein interactions is essential for understanding biological processes. Chemical cross-linking combined with mass spectrometry is an attractive approach for studying protein-protein interactions and protein structure, but to date its use has been limited largely by low yields of informative cross-links (because of inefficient cross-linking reactions) and by the difficulty of confidently identifying the sequences of cross-linked peptide pairs from their fragmentation spectra. Here we present an approach based on a new MS labile cross-linking reagent, BDRG (biotin-aspartate-Rink-glycine), which addresses these issues. BDRG incorporates a biotin handle (for enrichment of cross-linked peptides prior to MS analysis), two pentafluorophenyl ester groups that react with peptide amines, and a labile Rink-based bond between the pentafluorophenyl groups that allows cross-linked peptides to be separated during MS and confidently identified by database searching of their fragmentation spectra. We developed a protocol for the identification of BDRG cross-linked peptides derived from purified or partially purified protein complexes, including software to aid in the identification of different classes of cross-linker-modified peptides. Importantly, our approach permits the use of high accuracy precursor mass measurements to verify the database search results. We demonstrate the utility of the approach by applying it to purified yeast TFIIE, a heterodimeric transcription factor complex, and to a single-step affinity-purified preparation of the 12-subunit RNA polymerase II complex. The results show that the method is effective at identifying cross-linked peptides derived from purified and partially purified protein complexes and provides complementary information to that from other structural approaches. As such, it is an attractive approach to study the topology of protein complexes.
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Affiliation(s)
- Jie Luo
- Institute for Systems Biology, Seattle, Washington 98109, USA
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33
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Abstract
The human HSPC280 protein belongs to a new family of low molecular weight proteins, which is only present in eukaryotes, and is absent in fungi. The solution structure of HSPC280 was determined using multidimensional NMR spectroscopy. The overall structure consists of three α-helices and four antiparallel β-strands and has a winged helix-like fold. However, HEPC280 is not a typical DNA-binding winged helix protein in that it lacks DNA-binding activity. Unlike most winged-helix proteins, HSPC280 has an unusually long 13-residue (P62-V74) wing 1 loop connecting the β3 and β4 strands of the protein. Molecules of HSPC280 have a positively charged surface on one side and a negatively charged surface on the other side of the protein structure. Comparisons with the C-terminal 80-residue domain of proteins in the Abra family reveal a conserved hydrophobic groove in the HSPC280 family, which may allow HSPC280 to interact with other proteins.
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Affiliation(s)
- Jinzhong Lin
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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34
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Seizl M, Larivière L, Pfaffeneder T, Wenzeck L, Cramer P. Mediator head subcomplex Med11/22 contains a common helix bundle building block with a specific function in transcription initiation complex stabilization. Nucleic Acids Res 2011; 39:6291-304. [PMID: 21498544 PMCID: PMC3152362 DOI: 10.1093/nar/gkr229] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mediator is a multiprotein co-activator of RNA polymerase (Pol) II transcription. Mediator contains a conserved core that comprises the ‘head’ and ‘middle’ modules. We present here a structure–function analysis of the essential Med11/22 heterodimer, a part of the head module. Med11/22 forms a conserved four-helix bundle domain with C-terminal extensions, which bind the central head subunit Med17. A highly conserved patch on the bundle surface is required for stable transcription pre-initiation complex formation on a Pol II promoter in vitro and in vivo and may recruit the general transcription factor TFIIH. The bundle domain fold is also present in the Mediator middle module subcomplex Med7/21 and is predicted in the Mediator heterodimers Med2/3, Med4/9, Med10/14 and Med28/30. The bundle domain thus represents a common building block that has been multiplied and functionally diversified during Mediator evolution in eukaryotes.
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Affiliation(s)
- Martin Seizl
- Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
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35
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Lefèvre S, Dumay-Odelot H, El-Ayoubi L, Budd A, Legrand P, Pinaud N, Teichmann M, Fribourg S. Structure-function analysis of hRPC62 provides insights into RNA polymerase III transcription initiation. Nat Struct Mol Biol 2011; 18:352-8. [PMID: 21358628 DOI: 10.1038/nsmb.1996] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 12/02/2010] [Indexed: 02/07/2023]
Abstract
The 17-subunit human RNA polymerase III (hPol III) transcribes small, untranslated RNA genes that are involved in the regulation of transcription, splicing and translation. hPol III subunits hRPC62, hRPC39 and hRPC32 form a stable ternary subcomplex required for promoter-specific transcription initiation by hPol III. Here, we report the crystal structure of hRPC62. This subunit folds as a four-tandem extended winged helix (eWH) protein that is structurally related to the transcription factor TFIIEα N terminus. Through biochemical analyses, we mapped the protein-protein interactions of hRPC62, hRPC32 and hRPC39. In addition, we demonstrated that hRPC62 and hRPC39 bind single-stranded and duplex DNA, respectively, in a sequence-independent manner. Overall, we shed light on structural similarities between the hPol III-specific subunit hRPC62 and TFIIEα and propose specific functions for hRPC39 and hRPC62 in transcription initiation by hPol III.
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36
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Sun M, Larivière L, Dengl S, Mayer A, Cramer P. A tandem SH2 domain in transcription elongation factor Spt6 binds the phosphorylated RNA polymerase II C-terminal repeat domain (CTD). J Biol Chem 2010; 285:41597-603. [PMID: 20926372 DOI: 10.1074/jbc.m110.144568] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Spt6 is an essential transcription elongation factor and histone chaperone that binds the C-terminal repeat domain (CTD) of RNA polymerase II. We show here that Spt6 contains a tandem SH2 domain with a novel structure and CTD-binding mode. The tandem SH2 domain binds to a serine 2-phosphorylated CTD peptide in vitro, whereas its N-terminal SH2 subdomain, which we previously characterized, does not. CTD binding requires a positively charged crevice in the C-terminal SH2 subdomain, which lacks the canonical phospho-binding pocket of SH2 domains and had previously escaped detection. The tandem SH2 domain is apparently required for transcription elongation in vivo as its deletion in cells is lethal in the presence of 6-azauracil.
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Affiliation(s)
- Mai Sun
- Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany
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37
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Cycling through transcription with the RNA polymerase F/E (RPB4/7) complex: structure, function and evolution of archaeal RNA polymerase. Res Microbiol 2010; 162:10-8. [PMID: 20863887 DOI: 10.1016/j.resmic.2010.09.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 08/16/2010] [Indexed: 11/22/2022]
Abstract
RNA polymerases (RNAPs) from the three domains of life, Bacteria, Archaea and Eukarya, are evolutionarily related and thus have common structural and functional features. Despite the radically different morphology of Archaea and Eukarya, their RNAP subunit composition and utilisation of basal transcription factors are almost identical. This review focuses on the multiple functions of the most prominent feature that differentiates these enzymes from the bacterial RNAP--a stalk-like protrusion, which consists of the heterodimeric F/E subcomplex. F/E is highly versatile, it facilitates DNA strand-separation during transcription initiation, increases processivity during the elongation phase of transcription and ensures efficient transcription termination.
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38
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Geiger SR, Lorenzen K, Schreieck A, Hanecker P, Kostrewa D, Heck AJ, Cramer P. RNA Polymerase I Contains a TFIIF-Related DNA-Binding Subcomplex. Mol Cell 2010; 39:583-94. [DOI: 10.1016/j.molcel.2010.07.028] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 06/15/2010] [Accepted: 06/29/2010] [Indexed: 01/09/2023]
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39
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Selective depletion of Sulfolobus solfataricus transcription factor E under heat shock conditions. J Bacteriol 2010; 192:2887-91. [PMID: 20363950 DOI: 10.1128/jb.01534-09] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Archaeal transcriptional machinery is similar to that of eukaryotes. We studied the fates of various components of the Sulfolobus solfataricus transcriptional apparatus under different stresses and found that in cells incubated at 90 degrees C for 1 h, transcription factor E (TFE) is selectively depleted, but its mRNA levels are increased. We discuss the implications of these findings.
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40
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Grünberg S, Reich C, Zeller ME, Bartlett MS, Thomm M. Rearrangement of the RNA polymerase subunit H and the lower jaw in archaeal elongation complexes. Nucleic Acids Res 2009; 38:1950-63. [PMID: 20040576 PMCID: PMC2847245 DOI: 10.1093/nar/gkp1190] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The lower jaws of archaeal RNA polymerase and eukaryotic RNA polymerase II include orthologous subunits H and Rpb5, respectively. The tertiary structure of H is very similar to the structure of the C-terminal domain of Rpb5, and both subunits are proximal to downstream DNA in pre-initiation complexes. Analyses of reconstituted euryarchaeal polymerase lacking subunit H revealed that H is important for open complex formation and initial transcription. Eukaryotic Rpb5 rescues activity of the ΔH enzyme indicating a strong conservation of function for this subunit from archaea to eukaryotes. Photochemical cross-linking in elongation complexes revealed a striking structural rearrangement of RNA polymerase, bringing subunit H near the transcribed DNA strand one helical turn downstream of the active center, in contrast to the positioning observed in preinitiation complexes. The rearrangement of subunits H and A′′ suggest a major conformational change in the archaeal RNAP lower jaw upon formation of the elongation complex.
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Affiliation(s)
- Sebastian Grünberg
- Lehrstuhl für Mikrobiologie, Universität Regensburg, 93053 Regensburg, Germany
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41
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Carter R, Drouin G. The increase in the number of subunits in eukaryotic RNA polymerase III relative to RNA polymerase II is due to the permanent recruitment of general transcription factors. Mol Biol Evol 2009; 27:1035-43. [PMID: 20026480 DOI: 10.1093/molbev/msp316] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The number of subunits of RNA polymerases (RNAPs) increases during evolution from 5 in eubacteria to 12 in archaea. In eukaryotes, which have at least three RNAPs, the number of subunits has expanded from 12 in RNA polymerase II (RNAPII) to 14 in RNA polymerase I (RNAPI) and to 17 in RNA polymerase III (RNAPIII). It was recently demonstrated that the two additional subunits found in RNAPI relative to RNAPII are homologous to TFIIF, a dimeric general transcription factor of RNAPII. Here, we extend this finding by demonstrating that four of the five RNAPIII-specific subunits are also homologous to transcription factors of RNAPII. We use the available evidence to propose an evolutionary history of the eukaryotic RNAPs and argue that the increases in the number of subunits that occurred in RNAPs I and III are due to the permanent recruitment of preexisting transcription factors.
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Affiliation(s)
- Robert Carter
- Département de biologie Université d'Ottawa, Ottawa, Ontario, Canada
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42
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Korkhin Y, Unligil UM, Littlefield O, Nelson PJ, Stuart DI, Sigler PB, Bell SD, Abrescia NGA. Evolution of complex RNA polymerases: the complete archaeal RNA polymerase structure. PLoS Biol 2009; 7:e1000102. [PMID: 19419240 PMCID: PMC2675907 DOI: 10.1371/journal.pbio.1000102] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 03/19/2009] [Indexed: 11/19/2022] Open
Abstract
The archaeal RNA polymerase (RNAP) shares structural similarities with eukaryotic RNAP II but requires a reduced subset of general transcription factors for promoter-dependent initiation. To deepen our knowledge of cellular transcription, we have determined the structure of the 13-subunit DNA-directed RNAP from Sulfolobus shibatae at 3.35 Å resolution. The structure contains the full complement of subunits, including RpoG/Rpb8 and the equivalent of the clamp-head and jaw domains of the eukaryotic Rpb1. Furthermore, we have identified subunit Rpo13, an RNAP component in the order Sulfolobales, which contains a helix-turn-helix motif that interacts with the RpoH/Rpb5 and RpoA'/Rpb1 subunits. Its location and topology suggest a role in the formation of the transcription bubble.
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Affiliation(s)
- Yakov Korkhin
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, United States of America
| | - Ulug M Unligil
- Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, United States of America
| | - Otis Littlefield
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, United States of America
| | - Pamlea J Nelson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- Howard Hughes Medical Institute, Harvard University, Boston, Massachusetts, United States of America
| | - David I Stuart
- Division of Structural Biology and the Oxford Protein Production Facility, The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Paul B Sigler
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Howard Hughes Medical Institute, Yale University, New Haven, Connecticut, United States of America
| | - Stephen D Bell
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Nicola G. A Abrescia
- Division of Structural Biology and the Oxford Protein Production Facility, The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Structural Biology Unit, CIC bioGUNE, Derio, Spain
- * To whom correspondence should be addressed. E-mail:
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43
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Structure and in vivo requirement of the yeast Spt6 SH2 domain. J Mol Biol 2009; 389:211-25. [PMID: 19371747 DOI: 10.1016/j.jmb.2009.04.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 04/03/2009] [Accepted: 04/07/2009] [Indexed: 11/24/2022]
Abstract
During transcription elongation through chromatin, the Ser2-phosphorylated C-terminal repeat domain of RNA polymerase II binds the C-terminal Src homology 2 (SH2) domain of the nucleosome re-assembly factor Spt6. This SH2 domain is unusual in its specificity to bind phosphoserine, rather than phosphotyrosine and because it is the only SH2 domain in the yeast genome. Here, we report the high-resolution crystal structure of the SH2 domain from Candida glabrata Spt6. The structure combines features from both structural subfamilies of SH2 domains, suggesting it resembles a common ancestor of all SH2 domains. Two conserved surface pockets deviate from those of canonical SH2 domains, and may explain the unusual phosphoserine specificity. Differential gene expression analysis reveals that the SH2 domain is required for normal expression of a subset of yeast genes, and is consistent with multiple functions of Spt6 in chromatin transcription.
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44
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Mutational studies of archaeal RNA polymerase and analysis of hybrid RNA polymerases. Biochem Soc Trans 2009; 37:18-22. [PMID: 19143595 DOI: 10.1042/bst0370018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The recent success in reconstitution of RNAPs (RNA polymerases) from hyperthermophilic archaea from bacterially expressed purified subunits opens the way for detailed structure-function analyses of multisubunit RNAPs. The archaeal enzyme shows close structural similarity to eukaryotic RNAP, particularly to polymerase II, and can therefore be used as model for analyses of the eukaryotic transcriptional machinery. The cleft loops in the active centre of RNAP were deleted and modified to unravel their function in interaction with nucleic acids during transcription. The rudder, lid and fork 2 cleft loops were required for promoter-directed initiation and elongation, the rudder was essential for open complex formation. Analyses of transcripts from heteroduplex templates containing stable open complexes revealed that bubble reclosure is required for RNA displacement during elongation. Archaeal transcription systems contain, besides the orthologues of the eukaryotic transcription factors TBP (TATA-box-binding protein) and TF (transcription factor) IIB, an orthologue of the N-terminal part of the alpha subunit of eukaryotic TFIIE, called TFE, whose function is poorly understood. Recent analyses revealed that TFE is involved in open complex formation and, in striking contrast with eukaryotic TFIIE, is also present in elongation complexes. Recombinant archaeal RNAPs lacking specific subunits were used to investigate the functions of smaller subunits. These studies revealed that the subunits P and H, the orthologues of eukaryotic Rpb12 and Rpb5, were not required for RNAP assembly. Subunit P was essential for open complex formation, and the DeltaH enzyme was greatly impaired in all assays, with the exception of promoter recruitment. Recent reconstitution studies indicate that Rpb12 and Rpb5 can be incorporated into archaeal RNAP and can complement for the function of the corresponding archaeal subunit in in vitro transcription assays.
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45
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Tanaka A, Watanabe T, Iida Y, Hanaoka F, Ohkuma Y. Central forkhead domain of human TFIIE beta plays a primary role in binding double-stranded DNA at transcription initiation. Genes Cells 2009; 14:395-405. [PMID: 19210545 DOI: 10.1111/j.1365-2443.2008.01278.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human general transcription factor, TFIIE, consists of two subunits, alpha and beta. Structural analyses indicated the presence of a forkhead motif within the central region of TFIIEbeta. This motif was essential for transcription and possessed a double-stranded DNA-binding activity. Protein-DNA photo-cross-linking studies indicated that TFIIEbeta binds within the promoter region, adjacent to the transcription initiation site where promoter melting begins at transcription initiation. Furthermore, neither TFIIE nor the other general transcription factor TFIIH, were required for basal transcription of adenovirus major late promoter artificially pre-melted at the initiation site. These data suggest a model in which TFIIE binds to a position adjacent to the initiation site via the forkhead domain, enabling TFIIH to begin opening the promoter. Here, we used systematic point mutations to further investigate the functional roles of this domain. The mutant proteins were expressed in bacteria, purified and used to examine transcription of two different forms of template, phosphorylation of the C-terminal domain of RNA polymerase II, as well as dsDNA-binding. Taken together, our results strongly demonstrated that the primary function of the forkhead region is dsDNA-binding in transcription. In addition, we identified three positively charged lysine residues which play a key role in this function.
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Affiliation(s)
- Aki Tanaka
- Laboratory of Gene Regulation, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
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46
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Identification, structure, and functional requirement of the Mediator submodule Med7N/31. EMBO J 2008; 28:69-80. [PMID: 19057509 DOI: 10.1038/emboj.2008.254] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 11/07/2008] [Indexed: 12/24/2022] Open
Abstract
Mediator is a modular multiprotein complex required for regulated transcription by RNA polymerase (Pol) II. Here, we show that the middle module of the Mediator core contains a submodule of unique structure and function that comprises the N-terminal part of subunit Med7 (Med7N) and the highly conserved subunit Med31 (Soh1). The Med7N/31 submodule shows a conserved novel fold, with two proline-rich stretches in Med7N wrapping around the right-handed four-helix bundle of Med31. In vitro, Med7N/31 is required for activated transcription and can act in trans when added exogenously. In vivo, Med7N/31 has a predominantly positive function on the expression of a specific subset of genes, including genes involved in methionine metabolism and iron transport. Comparative phenotyping and transcriptome profiling identify specific and overlapping functions of different Mediator submodules.
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47
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Kuhn CD, Geiger SR, Baumli S, Gartmann M, Gerber J, Jennebach S, Mielke T, Tschochner H, Beckmann R, Cramer P. Functional architecture of RNA polymerase I. Cell 2008; 131:1260-72. [PMID: 18160037 DOI: 10.1016/j.cell.2007.10.051] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 10/02/2007] [Accepted: 10/26/2007] [Indexed: 01/10/2023]
Abstract
Synthesis of ribosomal RNA (rRNA) by RNA polymerase (Pol) I is the first step in ribosome biogenesis and a regulatory switch in eukaryotic cell growth. Here we report the 12 A cryo-electron microscopic structure for the complete 14-subunit yeast Pol I, a homology model for the core enzyme, and the crystal structure of the subcomplex A14/43. In the resulting hybrid structure of Pol I, A14/43, the clamp, and the dock domain contribute to a unique surface interacting with promoter-specific initiation factors. The Pol I-specific subunits A49 and A34.5 form a heterodimer near the enzyme funnel that acts as a built-in elongation factor and is related to the Pol II-associated factor TFIIF. In contrast to Pol II, Pol I has a strong intrinsic 3'-RNA cleavage activity, which requires the C-terminal domain of subunit A12.2 and, apparently, enables ribosomal RNA proofreading and 3'-end trimming.
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MESH Headings
- Binding Sites
- Cryoelectron Microscopy
- Crystallography, X-Ray
- DNA Polymerase I/chemistry
- DNA Polymerase I/genetics
- DNA Polymerase I/metabolism
- Models, Molecular
- Mutation
- Peptide Elongation Factors/chemistry
- Peptide Elongation Factors/metabolism
- Peptide Initiation Factors/chemistry
- Peptide Initiation Factors/metabolism
- Promoter Regions, Genetic
- Protein Conformation
- Protein Interaction Domains and Motifs
- Protein Interaction Mapping
- Protein Structure, Tertiary
- Protein Subunits
- RNA Processing, Post-Transcriptional
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- Saccharomyces cerevisiae/enzymology
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae Proteins/chemistry
- Saccharomyces cerevisiae Proteins/genetics
- Saccharomyces cerevisiae Proteins/metabolism
- Structure-Activity Relationship
- Transcription Factors, TFII/chemistry
- Transcription Factors, TFII/metabolism
- Transcription, Genetic
- Transcriptional Elongation Factors/chemistry
- Transcriptional Elongation Factors/metabolism
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Affiliation(s)
- Claus-D Kuhn
- Gene Center Munich and Center for Integrated Protein Science CIPSM, Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
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48
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Grünberg S, Bartlett MS, Naji S, Thomm M. Transcription factor E is a part of transcription elongation complexes. J Biol Chem 2007; 282:35482-90. [PMID: 17921145 DOI: 10.1074/jbc.m707371200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A homologue of the N-terminal domain of the alpha subunit of the general eukaryotic transcription factor TFE is encoded in the genomes of all sequenced archaea, but the position of archaeal TFE in transcription complexes has not yet been defined. We show here that TFE binds nonspecifically to single-stranded DNA, and photochemical cross-linking revealed TFE binding to a preformed open transcription bubble. In preinitiation complexes, the N-terminal part of TFE containing a winged helix-turn-helix motif is cross-linked specifically to DNA of the nontemplate DNA strand at positions -9 and -11. In complexes stalled at +20, TFE cross-linked specifically to positions +9, +11, and +16 of the non-template strand. Analyses of transcription complexes stalled at position +20 revealed a TFE-dependent increase of the resumption efficiency of stalled RNA polymerase and a TFE-induced enhanced permanganate sensitivity of thymine residues in the transcription bubble. These results demonstrate the presence of TFE in early elongation complexes and suggest a role of TFE in stabilization of the transcription bubble during elongation.
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Affiliation(s)
- Sebastian Grünberg
- Lehrstuhl für Mikrobiologie, Universitaet Regensburg, 93053 Regensburg, Germany
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49
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Kusser AG, Bertero MG, Naji S, Becker T, Thomm M, Beckmann R, Cramer P. Structure of an archaeal RNA polymerase. J Mol Biol 2007; 376:303-7. [PMID: 18164030 DOI: 10.1016/j.jmb.2007.08.066] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Revised: 08/24/2007] [Accepted: 08/28/2007] [Indexed: 10/22/2022]
Abstract
Related multisubunit RNA polymerases (RNAPs) carry out gene transcription in all kingdoms of life. Since structural information is limited to bacterial and eukaryotic RNAPs, we determined the cryo-electron microscopic structure of the RNAP from the thermophilic archaeon Pyrococcus furiosus at 13 A resolution. Comparison with eukaryotic RNAP II reveals a conserved architecture, no homologues for subunits Rpb8 and Rpb9, and significant deviation in the polymerase foot, jaws, pore, and protrusion. The structural organization of the archaeal RNA polymerase serves as a reference for future structure-function analysis of the transcription mechanism and allows for evolutionary comparisons.
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Affiliation(s)
- Anselm G Kusser
- Gene Center Munich and Center for integrated Protein Science CiPS(M), Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
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50
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Abstract
RNA polymerases (RNAPs) are essential to all life forms and therefore deserve our special attention. The archaeal RNAP is closely related to eukaryotic RNAPII in terms of subunit composition and architecture, promoter elements and basal transcription factors required for the initiation and elongation phase of transcription. RNAPs of this class are large and sophisticated enzymes that interact in a complex manner with DNA/RNA scaffolds, substrates NTPs and a plethora of transcription factors - interactions that often result in an allosteric regulation of RNAP activity. The 12 subunits of RNAP play distinct roles including RNAP assembly and stability, catalysis and functional contacts with exogenous factors. Due to the availability of structural information of RNAPs at high-resolution and wholly recombinant archaeal transcription systems, we are beginning to understand the molecular mechanisms of archaeal RNAPs and transcription in great detail.
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Affiliation(s)
- Finn Werner
- University College London, Department of Biochemistry and Molecular Biology, Darwin Building, Gower Street, London WC1E 6BT, UK.
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