1
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Wenck BR, Vickerman RL, Burkhart BW, Santangelo TJ. Archaeal histone-based chromatin structures regulate transcription elongation rates. Commun Biol 2024; 7:236. [PMID: 38413771 PMCID: PMC10899632 DOI: 10.1038/s42003-024-05928-w] [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: 08/16/2023] [Accepted: 02/16/2024] [Indexed: 02/29/2024] Open
Abstract
Many archaea encode and express histone proteins to compact their genomes. Archaeal and eukaryotic histones share a near-identical fold that permits DNA wrapping through select histone-DNA contacts to generate chromatin-structures that must be traversed by RNA polymerase (RNAP) to generate transcripts. As archaeal histones can spontaneously assemble with a single histone isoform, single-histone chromatin variants provide an idealized platform to detail the impacts of distinct histone-DNA contacts on transcription efficiencies and to detail the role of the conserved cleavage stimulatory factor, Transcription Factor S (TFS), in assisting RNAP through chromatin landscapes. We demonstrate that substitution of histone residues that modify histone-DNA contacts or the three-dimensional chromatin structure result in radically altered transcription elongation rates and pausing patterns. Chromatin-barriers slow and pause RNAP, providing regulatory potential. The modest impacts of TFS on elongation rates through chromatin landscapes is correlated with TFS-dispensability from the archaeon Thermococcus kodakarensis. Our results detail the importance of distinct chromatin structures for archaeal gene expression and provide a unique perspective on the evolution of, and regulatory strategies imposed by, eukaryotic chromatin.
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Affiliation(s)
- Breanna R Wenck
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Robert L Vickerman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Brett W Burkhart
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA
| | - Thomas J Santangelo
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, 80523, USA.
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2
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Blombach F, Sýkora M, Case J, Feng X, Baquero DP, Fouqueau T, Phung DK, Barker D, Krupovic M, She Q, Werner F. Cbp1 and Cren7 form chromatin-like structures that ensure efficient transcription of long CRISPR arrays. Nat Commun 2024; 15:1620. [PMID: 38388540 PMCID: PMC10883916 DOI: 10.1038/s41467-024-45728-8] [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: 04/05/2023] [Accepted: 02/01/2024] [Indexed: 02/24/2024] Open
Abstract
CRISPR arrays form the physical memory of CRISPR adaptive immune systems by incorporating foreign DNA as spacers that are often AT-rich and derived from viruses. As promoter elements such as the TATA-box are AT-rich, CRISPR arrays are prone to harbouring cryptic promoters. Sulfolobales harbour extremely long CRISPR arrays spanning several kilobases, a feature that is accompanied by the CRISPR-specific transcription factor Cbp1. Aberrant Cbp1 expression modulates CRISPR array transcription, but the molecular mechanisms underlying this regulation are unknown. Here, we characterise the genome-wide Cbp1 binding at nucleotide resolution and characterise the binding motifs on distinct CRISPR arrays, as well as on unexpected non-canonical binding sites associated with transposons. Cbp1 recruits Cren7 forming together 'chimeric' chromatin-like structures at CRISPR arrays. We dissect Cbp1 function in vitro and in vivo and show that the third helix-turn-helix domain is responsible for Cren7 recruitment, and that Cbp1-Cren7 chromatinization plays a dual role in the transcription of CRISPR arrays. It suppresses spurious transcription from cryptic promoters within CRISPR arrays but enhances CRISPR RNA transcription directed from their cognate promoters in their leader region. Our results show that Cbp1-Cren7 chromatinization drives the productive expression of long CRISPR arrays.
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Affiliation(s)
- Fabian Blombach
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
| | - Michal Sýkora
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Jo Case
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Xu Feng
- CRISPR and Archaea Biology Research Center, Microbial Technology Institute, Shandong University, Qingdao, 266237, PR China
| | - Diana P Baquero
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, F-75015, Paris, France
| | - Thomas Fouqueau
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Duy Khanh Phung
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Declan Barker
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, F-75015, Paris, France
| | - Qunxin She
- CRISPR and Archaea Biology Research Center, Microbial Technology Institute, Shandong University, Qingdao, 266237, PR China
| | - Finn Werner
- RNAP laboratory, Institute for Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
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3
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Lorch Y, Kornberg RD, Maier-Davis B. Role of the histone tails in histone octamer transfer. Nucleic Acids Res 2023; 51:3671-3678. [PMID: 36772826 PMCID: PMC10164550 DOI: 10.1093/nar/gkad079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/17/2023] [Accepted: 01/25/2023] [Indexed: 02/12/2023] Open
Abstract
The exceptionally high positive charge of the histones, concentrated in the N- and C-terminal tails, is believed to contribute to the stability of the nucleosome by neutralizing the negative charge of the nucleosomal DNA. We find, on the contrary, that the high positive charge contributes to instability, performing an essential function in chromatin remodeling. We show that the tails are required for removal of the histone octamer by the RSC chromatin remodeling complex, and this function is not due to direct RSC-tail interaction. We also show that the tails are required for histone octamer transfer from nucleosomes to DNA, and this activity of the tails is a consequence of their positive charge. Thus, the histone tails, intrinsically disordered protein regions, perform a critical role in chromatin structure and transcription, unrelated to their well-known role in regulation through posttranscriptional modification.
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Affiliation(s)
- Yahli Lorch
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roger D Kornberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Barbara Maier-Davis
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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4
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Sakrikar S, Schmid A. An archaeal histone-like protein regulates gene expression in response to salt stress. Nucleic Acids Res 2021; 49:12732-12743. [PMID: 34883507 PMCID: PMC8682779 DOI: 10.1093/nar/gkab1175] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 12/21/2022] Open
Abstract
Histones, ubiquitous in eukaryotes as DNA-packing proteins, find their evolutionary origins in archaea. Unlike the characterized histone proteins of a number of methanogenic and themophilic archaea, previous research indicated that HpyA, the sole histone encoded in the model halophile Halobacterium salinarum, is not involved in DNA packaging. Instead, it was found to have widespread but subtle effects on gene expression and to maintain wild type cell morphology. However, the precise function of halophilic histone-like proteins remain unclear. Here we use quantitative phenotyping, genetics, and functional genomics to investigate HpyA function. These experiments revealed that HpyA is important for growth and rod-shaped morphology in reduced salinity. HpyA preferentially binds DNA at discrete genomic sites under low salt to regulate expression of ion uptake, particularly iron. HpyA also globally but indirectly activates other ion uptake and nucleotide biosynthesis pathways in a salt-dependent manner. Taken together, these results demonstrate an alternative function for an archaeal histone-like protein as a transcriptional regulator, with its function tuned to the physiological stressors of the hypersaline environment.
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Affiliation(s)
- Saaz Sakrikar
- Biology Department, Duke University, Durham, NC27708, USA
- University Program in Genetics and Genomics, Duke University, Durham, NC27708, USA
| | - Amy K Schmid
- Biology Department, Duke University, Durham, NC27708, USA
- University Program in Genetics and Genomics, Duke University, Durham, NC27708, USA
- Center for Genomics and Computational Biology, Duke University, Durham, NC27708, USA
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5
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Villain P, da Cunha V, Villain E, Forterre P, Oberto J, Catchpole R, Basta T. The hyperthermophilic archaeon Thermococcus kodakarensis is resistant to pervasive negative supercoiling activity of DNA gyrase. Nucleic Acids Res 2021; 49:12332-12347. [PMID: 34755863 PMCID: PMC8643681 DOI: 10.1093/nar/gkab869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/10/2021] [Accepted: 11/02/2021] [Indexed: 01/15/2023] Open
Abstract
In all cells, DNA topoisomerases dynamically regulate DNA supercoiling allowing essential DNA processes such as transcription and replication to occur. How this complex system emerged in the course of evolution is poorly understood. Intriguingly, a single horizontal gene transfer event led to the successful establishment of bacterial gyrase in Archaea, but its emergent function remains a mystery. To better understand the challenges associated with the establishment of pervasive negative supercoiling activity, we expressed the gyrase of the bacterium Thermotoga maritima in a naïve archaeon Thermococcus kodakarensis which naturally has positively supercoiled DNA. We found that the gyrase was catalytically active in T. kodakarensis leading to strong negative supercoiling of plasmid DNA which was stably maintained over at least eighty generations. An increased sensitivity of gyrase-expressing T. kodakarensis to ciprofloxacin suggested that gyrase also modulated chromosomal topology. Accordingly, global transcriptome analyses revealed large scale gene expression deregulation and identified a subset of genes responding to the negative supercoiling activity of gyrase. Surprisingly, the artificially introduced dominant negative supercoiling activity did not have a measurable effect on T. kodakarensis growth rate. Our data suggest that gyrase can become established in Thermococcales archaea without critically interfering with DNA transaction processes.
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Affiliation(s)
- Paul Villain
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Violette da Cunha
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | | | - Patrick Forterre
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.,Archaeal Virology Unit, Institut Pasteur, Paris, France
| | - Jacques Oberto
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Ryan Catchpole
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Tamara Basta
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
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6
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Phan HD, Lai LB, Zahurancik WJ, Gopalan V. The many faces of RNA-based RNase P, an RNA-world relic. Trends Biochem Sci 2021; 46:976-991. [PMID: 34511335 DOI: 10.1016/j.tibs.2021.07.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/11/2021] [Accepted: 07/28/2021] [Indexed: 12/24/2022]
Abstract
RNase P is an essential enzyme that catalyzes removal of the 5' leader from precursor transfer RNAs. The ribonucleoprotein (RNP) form of RNase P is present in all domains of life and comprises a single catalytic RNA (ribozyme) and a variable number of protein cofactors. Recent cryo-electron microscopy structures of representative archaeal and eukaryotic (nuclear) RNase P holoenzymes bound to tRNA substrate/product provide high-resolution detail on subunit organization, topology, and substrate recognition in these large, multisubunit catalytic RNPs. These structures point to the challenges in understanding how proteins modulate the RNA functional repertoire and how the structure of an ancient RNA-based catalyst was reshaped during evolution by new macromolecular associations that were likely necessitated by functional/regulatory coupling.
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Affiliation(s)
- Hong-Duc Phan
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Lien B Lai
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.
| | - Walter J Zahurancik
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Venkat Gopalan
- Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA; Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.
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7
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Sanders TJ, Ullah F, Gehring AM, Burkhart BW, Vickerman RL, Fernando S, Gardner AF, Ben-Hur A, Santangelo TJ. Extended Archaeal Histone-Based Chromatin Structure Regulates Global Gene Expression in Thermococcus kodakarensis. Front Microbiol 2021; 12:681150. [PMID: 34054788 PMCID: PMC8155482 DOI: 10.3389/fmicb.2021.681150] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
Histone proteins compact and organize DNA resulting in a dynamic chromatin architecture impacting DNA accessibility and ultimately gene expression. Eukaryotic chromatin landscapes are structured through histone protein variants, epigenetic marks, the activities of chromatin-remodeling complexes, and post-translational modification of histone proteins. In most Archaea, histone-based chromatin structure is dominated by the helical polymerization of histone proteins wrapping DNA into a repetitive and closely gyred configuration. The formation of the archaeal-histone chromatin-superhelix is a regulatory force of adaptive gene expression and is likely critical for regulation of gene expression in all histone-encoding Archaea. Single amino acid substitutions in archaeal histones that block formation of tightly packed chromatin structures have profound effects on cellular fitness, but the underlying gene expression changes resultant from an altered chromatin landscape have not been resolved. Using the model organism Thermococcus kodakarensis, we genetically alter the chromatin landscape and quantify the resultant changes in gene expression, including unanticipated and significant impacts on provirus transcription. Global transcriptome changes resultant from varying chromatin landscapes reveal the regulatory importance of higher-order histone-based chromatin architectures in regulating archaeal gene expression.
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Affiliation(s)
- Travis J. Sanders
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Fahad Ullah
- Department of Computer Science, Colorado State University, Fort Collins, CO, United States
| | - Alexandra M. Gehring
- Molecular Enzymology Division, New England Biolabs, Inc., Ipswich, MA, United States
| | - Brett W. Burkhart
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Robert L. Vickerman
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Sudili Fernando
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
| | - Andrew F. Gardner
- Molecular Enzymology Division, New England Biolabs, Inc., Ipswich, MA, United States
| | - Asa Ben-Hur
- Department of Computer Science, Colorado State University, Fort Collins, CO, United States
| | - Thomas J. Santangelo
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, United States
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8
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Abstract
Determining whether and how a gene is transcribed are two of the central processes of life. The conceptual basis for understanding such gene regulation arose from pioneering biophysical studies in eubacteria. However, eukaryotic genomes exhibit vastly greater complexity, which raises questions not addressed by this bacterial paradigm. First, how is information integrated from many widely separated binding sites to determine how a gene is transcribed? Second, does the presence of multiple energy-expending mechanisms, which are absent from eubacterial genomes, indicate that eukaryotes are capable of improved forms of genetic information processing? An updated biophysical foundation is needed to answer such questions. We describe the linear framework, a graph-based approach to Markov processes, and show that it can accommodate many previous studies in the field. Under the assumption of thermodynamic equilibrium, we introduce a language of higher-order cooperativities and show how it can rigorously quantify gene regulatory properties suggested by experiment. We point out that fundamental limits to information processing arise at thermodynamic equilibrium and can only be bypassed through energy expenditure. Finally, we outline some of the mathematical challenges that must be overcome to construct an improved biophysical understanding of gene regulation.
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Affiliation(s)
- Felix Wong
- Institute for Medical Engineering & Science, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Jeremy Gunawardena
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA;
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9
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Thiroux S, Dupont S, Nesbø CL, Bienvenu N, Krupovic M, L'Haridon S, Marie D, Forterre P, Godfroy A, Geslin C. The first head-tailed virus, MFTV1, infecting hyperthermophilic methanogenic deep-sea archaea. Environ Microbiol 2020; 23:3614-3626. [PMID: 33022088 DOI: 10.1111/1462-2920.15271] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/20/2020] [Accepted: 10/03/2020] [Indexed: 11/27/2022]
Abstract
Deep-sea hydrothermal vents are inhabited by complex communities of microbes and their viruses. Despite the importance of viruses in controlling the diversity, adaptation and evolution of their microbial hosts, to date, only eight bacterial and two archaeal viruses isolated from abyssal ecosystems have been described. Thus, our efforts focused on gaining new insights into viruses associated with deep-sea autotrophic archaea. Here, we provide the first evidence of an infection of hyperthermophilic methanogenic archaea by a head-tailed virus, Methanocaldococcus fervens tailed virus 1 (MFTV1). MFTV1 has an isometric head of 50 nm in diameter and a 150 nm-long non-contractile tail. Virions are released continuously without causing a sudden drop in host growth. MFTV1 infects Methanocaldococcus species and is the first hyperthermophilic head-tailed virus described thus far. The viral genome is a double-stranded linear DNA of 31 kb. Interestingly, our results suggest potential strategies adopted by the plasmid pMEFER01, carried by M. fervens, to spread horizontally in hyperthermophilic methanogens. The data presented here open a new window of understanding on how the abyssal mobilome interacts with hyperthermophilic marine archaea.
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Affiliation(s)
- Sarah Thiroux
- Laboratoire de Microbiologie des Environnements Extrêmes, Univ Brest, CNRS, IFREMER, Plouzané, F-29280, France
| | - Samuel Dupont
- Laboratoire de Microbiologie des Environnements Extrêmes, Univ Brest, CNRS, IFREMER, Plouzané, F-29280, France
| | - Camilla L Nesbø
- Biozone, University of Toronto, Toronto, Ontario, M5S 3E5, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G2R3, 12, Canada
| | - Nadège Bienvenu
- Laboratoire de Microbiologie des Environnements Extrêmes, Univ Brest, CNRS, IFREMER, Plouzané, F-29280, France
| | - Mart Krupovic
- Archaeal Virology Unit, Institut Pasteur, Paris, 75015, France
| | - Stéphane L'Haridon
- Laboratoire de Microbiologie des Environnements Extrêmes, Univ Brest, CNRS, IFREMER, Plouzané, F-29280, France
| | - Dominique Marie
- UPMC Univ Paris 06, INSU-CNRS, UMR 7144, Station Biologique de Roscoff, Sorbonne University, Roscoff, 29680, France
| | - Patrick Forterre
- Archaeal Virology Unit, Institut Pasteur, Paris, 75015, France.,Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS., Gif-sur-Yvette, 91198, France
| | - Anne Godfroy
- Laboratoire de Microbiologie des Environnements Extrêmes, Univ Brest, CNRS, IFREMER, Plouzané, F-29280, France
| | - Claire Geslin
- Laboratoire de Microbiologie des Environnements Extrêmes, Univ Brest, CNRS, IFREMER, Plouzané, F-29280, France
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10
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Wenck BR, Santangelo TJ. Archaeal transcription. Transcription 2020; 11:199-210. [PMID: 33112729 PMCID: PMC7714419 DOI: 10.1080/21541264.2020.1838865] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022] Open
Abstract
Increasingly sophisticated biochemical and genetic techniques are unraveling the regulatory factors and mechanisms that control gene expression in the Archaea. While some similarities in regulatory strategies are universal, archaeal-specific regulatory strategies are emerging to complement a complex patchwork of shared archaeal-bacterial and archaeal-eukaryotic regulatory mechanisms employed in the archaeal domain. The prokaryotic archaea encode core transcription components with homology to the eukaryotic transcription apparatus and also share a simplified eukaryotic-like initiation mechanism, but also deploy tactics common to bacterial systems to regulate promoter usage and influence elongation-termination decisions. We review the recently established complete archaeal transcription cycle, highlight recent findings of the archaeal transcription community and detail the expanding post-initiation regulation imposed on archaeal transcription.
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Affiliation(s)
- Breanna R. Wenck
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Thomas J. Santangelo
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
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11
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Kornberg RD, Lorch Y. Primary Role of the Nucleosome. Mol Cell 2020; 79:371-375. [PMID: 32763226 DOI: 10.1016/j.molcel.2020.07.020] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 12/16/2019] [Accepted: 03/10/2020] [Indexed: 11/18/2022]
Abstract
Whereas the core nucleosome is thought to serve as a packaging device for the coiling and contraction in length of genomic DNA, we suggest that it serves primarily in the regulation of transcription. A nucleosome on a promoter prevents the initiation of transcription. The association of nucleosomes with most genomic DNA prevents initiation from cryptic promoters. The nucleosome thus serves not only as a general gene repressor, but also as a repressor of all transcription (genic, intragenic, and intergenic). The core nucleosome performs a fundamental regulatory role, apart from the histone "tails," which modulate gene activity.
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Affiliation(s)
- Roger D Kornberg
- Department of Structural Biology, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Yahli Lorch
- Department of Structural Biology, Stanford School of Medicine, Stanford, CA 94305, USA.
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12
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Maruyama H, Prieto EI, Nambu T, Mashimo C, Kashiwagi K, Okinaga T, Atomi H, Takeyasu K. Different Proteins Mediate Step-Wise Chromosome Architectures in Thermoplasma acidophilum and Pyrobaculum calidifontis. Front Microbiol 2020; 11:1247. [PMID: 32655523 PMCID: PMC7325993 DOI: 10.3389/fmicb.2020.01247] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/15/2020] [Indexed: 12/15/2022] Open
Abstract
Archaeal species encode a variety of distinct lineage-specific chromosomal proteins. We have previously shown that in Thermococcus kodakarensis, histone, Alba, and TrmBL2 play distinct roles in chromosome organization. Although our understanding of individual archaeal chromosomal proteins has been advancing, how archaeal chromosomes are folded into higher-order structures and how they are regulated are largely unknown. Here, we investigated the primary and higher-order structures of archaeal chromosomes from different archaeal lineages. Atomic force microscopy of chromosome spreads out of Thermoplasma acidophilum and Pyrobaculum calidifontis cells revealed 10-nm fibers and 30–40-nm globular structures, suggesting the occurrence of higher-order chromosomal folding. Our results also indicated that chromosome compaction occurs toward the stationary phase. Micrococcal nuclease digestion indicated that fundamental structural units of the chromosome exist in T. acidophilum and T. kodakarensis but not in P. calidifontis or Sulfolobus solfataricus. In vitro reconstitution showed that, in T. acidophilum, the bacterial HU protein homolog HTa formed a 6-nm fiber by wrapping DNA, and that Alba was responsible for the formation of the 10-nm fiber by binding along the DNA without wrapping. Remarkably, Alba could form different higher-order complexes with histone or HTa on DNA in vitro. Mass spectrometry detected HTa and Rad50 in the T. acidophilum chromosome but not in other species. A putative transcriptional regulator of the AsnC/Lrp family (Pcal_1183) was detected on the P. calidifontis chromosome, but not on that of other species studied. Putative membrane-associated proteins were detected in the chromosomes of the three archaeal species studied, including T. acidophilum, P. calidifontis, and T. kodakarensis. Collectively, our data show that Archaea use different combinations of proteins to achieve chromosomal architecture and functional regulation.
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Affiliation(s)
- Hugo Maruyama
- Department of Bacteriology, Osaka Dental University, Hirakata, Japan
| | - Eloise I Prieto
- National Institute of Molecular Biology and Biotechnology, College of Science, University of the Philippines Diliman, Quezon City, Philippines
| | - Takayuki Nambu
- Department of Bacteriology, Osaka Dental University, Hirakata, Japan
| | - Chiho Mashimo
- Department of Bacteriology, Osaka Dental University, Hirakata, Japan
| | - Kosuke Kashiwagi
- Department of Fixed Prosthodontics, Osaka Dental University, Hirakata, Japan
| | - Toshinori Okinaga
- Department of Bacteriology, Osaka Dental University, Hirakata, Japan
| | - Haruyuki Atomi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Kunio Takeyasu
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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13
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Abstract
Over the past decade, advances in methodologies for the determination of chromosome conformation have provided remarkable insight into the local and higher-order organization of bacterial and eukaryotic chromosomes. Locally folded domains are found in both bacterial and eukaryotic genomes, although they vary in size. Importantly, genomes of metazoans also possess higher-order organization into A- and B-type compartments, regions of transcriptionally active and inactive chromatin, respectively. Until recently, nothing was known about the organization of genomes of organisms in the third domain of life - the archaea. However, despite archaea possessing simple circular genomes that are morphologically reminiscent of those seen in many bacteria, a recent study of archaea of the genus Sulfolobus has revealed that it organizes its genome into large-scale domains. These domains further interact to form defined A- and B-type compartments. The interplay of transcription and localization of a novel structural maintenance of chromosomes (SMC) superfamily protein, termed coalescin, defines compartment identity. In this Review, we discuss the mechanistic and evolutionary implications of these findings.
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Affiliation(s)
- Naomichi Takemata
- Biology Department, Indiana University, Bloomington, USA.,Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, USA
| | - Stephen D Bell
- Biology Department, Indiana University, Bloomington, USA .,Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, USA
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14
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Sanders TJ, Wenck BR, Selan JN, Barker MP, Trimmer SA, Walker JE, Santangelo TJ. FttA is a CPSF73 homologue that terminates transcription in Archaea. Nat Microbiol 2020; 5:545-553. [PMID: 32094586 PMCID: PMC7103508 DOI: 10.1038/s41564-020-0667-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 01/06/2020] [Indexed: 12/23/2022]
Abstract
Regulated gene expression is largely achieved by controlling the activities of essential, multisubunit RNA polymerase transcription elongation complexes (TECs). The extreme stability required of TECs to processively transcribe large genomic regions necessitates robust mechanisms to terminate transcription. Efficient transcription termination is particularly critical for gene-dense bacterial and archaeal genomes1-3 in which continued transcription would necessarily transcribe immediately adjacent genes and result in conflicts between the transcription and replication apparatuses4-6; the coupling of transcription and translation7,8 would permit the loading of ribosomes onto aberrant transcripts. Only select sequences or transcription termination factors can disrupt the otherwise extremely stable TEC and we demonstrate that one of the last universally conserved archaeal proteins with unknown biological function is the Factor that terminates transcription in Archaea (FttA). FttA resolves the dichotomy of a prokaryotic gene structure (operons and polarity) and eukaryotic molecular homology (general transcription apparatus) that is observed in Archaea. This missing link between prokaryotic and eukaryotic transcription regulation provides the most parsimonious link to the evolution of the processing activities involved in RNA 3'-end formation in Eukarya.
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Affiliation(s)
- Travis J Sanders
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Breanna R Wenck
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Jocelyn N Selan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Mathew P Barker
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Stavros A Trimmer
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Julie E Walker
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
- Watchmaker Genomics, Boulder, CO, USA
| | - Thomas J Santangelo
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
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15
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Shen BA, Landick R. Transcription of Bacterial Chromatin. J Mol Biol 2019; 431:4040-4066. [PMID: 31153903 PMCID: PMC7248592 DOI: 10.1016/j.jmb.2019.05.041] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022]
Abstract
Decades of research have probed the interplay between chromatin (genomic DNA associated with proteins and RNAs) and transcription by RNA polymerase (RNAP) in all domains of life. In bacteria, chromatin is compacted into a membrane-free region known as the nucleoid that changes shape and composition depending on the bacterial state. Transcription plays a key role in both shaping the nucleoid and organizing it into domains. At the same time, chromatin impacts transcription by at least five distinct mechanisms: (i) occlusion of RNAP binding; (ii) roadblocking RNAP progression; (iii) constraining DNA topology; (iv) RNA-mediated interactions; and (v) macromolecular demixing and heterogeneity, which may generate phase-separated condensates. These mechanisms are not mutually exclusive and, in combination, mediate gene regulation. Here, we review the current understanding of these mechanisms with a focus on gene silencing by H-NS, transcription coordination by HU, and potential phase separation by Dps. The myriad questions about transcription of bacterial chromatin are increasingly answerable due to methodological advances, enabling a needed paradigm shift in the field of bacterial transcription to focus on regulation of genes in their native state. We can anticipate answers that will define how bacterial chromatin helps coordinate and dynamically regulate gene expression in changing environments.
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Affiliation(s)
- Beth A Shen
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Robert Landick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, United States.
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16
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The TK0271 Protein Activates Transcription of Aromatic Amino Acid Biosynthesis Genes in the Hyperthermophilic Archaeon Thermococcus kodakarensis. mBio 2019; 10:mBio.01213-19. [PMID: 31506306 PMCID: PMC6737238 DOI: 10.1128/mbio.01213-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mechanisms of transcriptional regulation in archaea are still poorly understood. In this study, we identified a transcriptional regulator in the hyperthermophilic archaeon Thermococcus kodakarensis that activates the transcription of three operons involved in the biosynthesis of aromatic amino acids. The study represents one of only a few that identifies a regulator in Archaea that activates transcription. The results also imply that transcriptional regulation of genes with the same function is carried out by diverse mechanisms in the archaea, depending on the lineage. TrpY from Methanothermobacter thermautotrophicus is a regulator that inhibits transcription of the Trp biosynthesis (trp) operon. Here, we show that the TrpY homolog in Thermococcus kodakarensis is not involved in such regulation. There are 87 genes on the T. kodakarensis genome predicted to encode transcriptional regulators (TRs). By screening for TRs that specifically bind to the promoter of the trp operon of T. kodakarensis, we identified TK0271. The gene resides in the aro operon, responsible for the biosynthesis of chorismate, a precursor for Trp, Tyr, and Phe. TK0271 was expressed in Escherichia coli, and the protein, here designated Tar (Thermococcalesaromatic amino acid regulator), was purified. Tar specifically bound to the trp promoter with a dissociation constant (Kd) value of approximately 5 nM. Tar also bound to the promoters of the Tyr/Phe biosynthesis (tyr-phe) and aro operons. The protein recognized a palindromic sequence (TGGACA-N8-TGTCCA) conserved in these promoters. In vitro transcription assays indicated that Tar activates transcription from all three promoters. We cultivated T. kodakarensis in amino acid-based medium and found that transcript levels of the trp, tyr-phe, and aro operons increased in the absence of Trp, Tyr, or Phe. We further constructed a TK0271 gene disruption strain (ΔTK0271). Growth of ΔTK0271 was similar to that of the host strain in medium including Trp, Tyr, and Phe but was significantly impaired in the absence of any one of these amino acids. The results suggest that Tar is responsible for the transcriptional activation of aromatic amino acid biosynthesis genes in T. kodakarensis.
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17
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Ebright RH, Werner F, Zhang X. RNA Polymerase Reaches 60: Transcription Initiation, Elongation, Termination, and Regulation in Prokaryotes. J Mol Biol 2019; 431:3945-3946. [PMID: 31356803 DOI: 10.1016/j.jmb.2019.07.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Richard H Ebright
- Waksman Institute and Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA.
| | - Finn Werner
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom
| | - Xiaodong Zhang
- Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, United Kingdom
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