1
|
Golov AK, Gavrilov AA. Cohesin Complex: Structure and Principles of Interaction with DNA. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:585-600. [PMID: 38831498 DOI: 10.1134/s0006297924040011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 06/05/2024]
Abstract
Accurate duplication and separation of long linear genomic DNA molecules is associated with a number of purely mechanical problems. SMC complexes are key components of the cellular machinery that ensures decatenation of sister chromosomes and compaction of genomic DNA during division. Cohesin, one of the essential eukaryotic SMC complexes, has a typical ring structure with intersubunit pore through which DNA molecules can be threaded. Capacity of cohesin for such topological entrapment of DNA is crucial for the phenomenon of post-replicative association of sister chromatids better known as cohesion. Recently, it became apparent that cohesin and other SMC complexes are, in fact, motor proteins with a very peculiar movement pattern leading to formation of DNA loops. This specific process has been called loop extrusion. Extrusion underlies multiple functions of cohesin beyond cohesion, but molecular mechanism of the process remains a mystery. In this review, we summarized the data on molecular architecture of cohesin, effect of ATP hydrolysis cycle on this architecture, and known modes of cohesin-DNA interactions. Many of the seemingly disparate facts presented here will probably be incorporated in a unified mechanistic model of loop extrusion in the not-so-distant future.
Collapse
Affiliation(s)
- Arkadiy K Golov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Technion - Israel Institute of Technology, Haifa, 3525433, Israel
| | - Alexey A Gavrilov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
| |
Collapse
|
2
|
Nasmyth KA, Lee BG, Roig MB, Löwe J. What AlphaFold tells us about cohesin's retention on and release from chromosomes. eLife 2023; 12:RP88656. [PMID: 37975572 PMCID: PMC10656103 DOI: 10.7554/elife.88656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023] Open
Abstract
Cohesin is a trimeric complex containing a pair of SMC proteins (Smc1 and Smc3) whose ATPase domains at the end of long coiled coils (CC) are interconnected by Scc1. During interphase, it organizes chromosomal DNA topology by extruding loops in a manner dependent on Scc1's association with two large hook-shaped proteins called SA (yeast: Scc3) and Nipbl (Scc2). The latter's replacement by Pds5 recruits Wapl, which induces release from chromatin via a process requiring dissociation of Scc1's N-terminal domain (NTD) from Smc3. If blocked by Esco (Eco)-mediated Smc3 acetylation, cohesin containing Pds5 merely maintains pre-existing loops, but a third fate occurs during DNA replication, when Pds5-containing cohesin associates with Sororin and forms structures that hold sister DNAs together. How Wapl induces and Sororin blocks release has hitherto remained mysterious. In the 20 years since their discovery, not a single testable hypothesis has been proposed as to their role. Here, AlphaFold 2 (AF) three-dimensional protein structure predictions lead us to propose formation of a quarternary complex between Wapl, SA, Pds5, and Scc1's NTD, in which the latter is juxtaposed with (and subsequently sequestered by) a highly conserved cleft within Wapl's C-terminal domain. AF also reveals how Scc1's dissociation from Smc3 arises from a distortion of Smc3's CC induced by engagement of SMC ATPase domains, how Esco acetyl transferases are recruited to Smc3 by Pds5, and how Sororin prevents release by binding to the Smc3/Scc1 interface. Our hypotheses explain the phenotypes of numerous existing mutations and are highly testable.
Collapse
Affiliation(s)
- Kim A Nasmyth
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Byung-Gil Lee
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | | | - Jan Löwe
- MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| |
Collapse
|
3
|
Tang M, Pobegalov G, Tanizawa H, Chen ZA, Rappsilber J, Molodtsov M, Noma KI, Uhlmann F. Establishment of dsDNA-dsDNA interactions by the condensin complex. Mol Cell 2023; 83:3787-3800.e9. [PMID: 37820734 PMCID: PMC10842940 DOI: 10.1016/j.molcel.2023.09.019] [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: 05/08/2023] [Revised: 08/13/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
Condensin is a structural maintenance of chromosomes (SMC) complex family member thought to build mitotic chromosomes by DNA loop extrusion. However, condensin variants unable to extrude loops, yet proficient in chromosome formation, were recently described. Here, we explore how condensin might alternatively build chromosomes. Using bulk biochemical and single-molecule experiments with purified fission yeast condensin, we observe that individual condensins sequentially and topologically entrap two double-stranded DNAs (dsDNAs). Condensin loading transitions through a state requiring DNA bending, as proposed for the related cohesin complex. While cohesin then favors the capture of a second single-stranded DNA (ssDNA), second dsDNA capture emerges as a defining feature of condensin. We provide complementary in vivo evidence for DNA-DNA capture in the form of condensin-dependent chromatin contacts within, as well as between, chromosomes. Our results support a "diffusion capture" model in which condensin acts in mitotic chromosome formation by sequential dsDNA-dsDNA capture.
Collapse
Affiliation(s)
- Minzhe Tang
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Georgii Pobegalov
- Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Hideki Tanizawa
- Division of Genome Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan
| | - Zhuo A Chen
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Juri Rappsilber
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany; Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Maxim Molodtsov
- Mechanobiology and Biophysics Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Ken-Ichi Noma
- Division of Genome Biology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido 060-0815, Japan; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Frank Uhlmann
- Chromosome Segregation Laboratory, The Francis Crick Institute, London NW1 1AT, UK; Cell Biology Centre, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-0026, Japan.
| |
Collapse
|
4
|
Moon KW, Ryu JK. Current working models of SMC-driven DNA-loop extrusion. Biochem Soc Trans 2023; 51:1801-1810. [PMID: 37767565 DOI: 10.1042/bst20220898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 09/17/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
Structural maintenance of chromosome (SMC) proteins play a key roles in the chromosome organization by condensing two meters of DNA into cell-sized structures considered as the SMC protein extrudes DNA loop. Recent sequencing-based high-throughput chromosome conformation capture technique (Hi-C) and single-molecule experiments have provided direct evidence of DNA-loop extrusion. However, the molecular mechanism by which SMCs extrude a DNA loop is still under debate. Here, we review DNA-loop extrusion studies with single-molecule assays and introduce recent structural studies of how the ATP-hydrolysis cycle is coupled to the conformational changes of SMCs for DNA-loop extrusion. In addition, we explain the conservation of the DNA-binding sites that are vital for dynamic DNA-loop extrusion by comparing Cryo-EM structures of SMC complexes. Based on this information, we compare and discuss four compelling working models that explain how the SMC complex extrudes a DNA loop.
Collapse
Affiliation(s)
- Kyoung-Wook Moon
- Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| | - Je-Kyung Ryu
- Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea
| |
Collapse
|
5
|
Wang H, Li Q, Zhang Z, Ayepa E, Xiang Q, Yu X, Zhao K, Zou L, Gu Y, Li X, Chen Q, Zhang X, Yang Y, Jin X, Yin H, Liu ZL, Tang T, Liu B, Ma M. Discovery of new strains for furfural degradation using adaptive laboratory evolution in Saccharomyces cerevisiae. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132090. [PMID: 37480608 DOI: 10.1016/j.jhazmat.2023.132090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/15/2023] [Accepted: 07/17/2023] [Indexed: 07/24/2023]
Abstract
In industrial production, the excessive discharge of furfural can pose harm to soil microorganisms, aquatic animals and plants, as well as humans. Therefore, it is crucial to develop efficient and cost-effective methods for degrading furfural in the environment. Currently, the use of Saccharomyces cerevisiae for furfural degradation in water has shown effectiveness, but there is a need to explore improved efficiency and tolerance in S. cerevisiae for this purpose. In this study, we isolated and evolved highly efficient furfural degradation strains, namely YBA_08 and F60C. These strains exhibited remarkable capabilities, degrading 59% and 99% furfural in the YPD medium after 72 h of incubation, significantly higher than the 31% achieved by the model strain S288C. Through analysis of the efficient degradation mechanism in the evolutionary strain F60C, we discovered a 326% increase in the total amount of NADH and NADPH. This increase likely promotes faster furfural degradation through intracellular aldehyde reductases. Moreover, the decrease in NADPH content led to a 406% increase in glutathione content at the background level, which protects cells from damage caused by reactive oxygen species. Mutations and differential expression related to cell cycle and cell wall synthesis were observed, enabling cell survival in the presence of furfural and facilitating rapid furfural degradation and growth recovery. Based on these findings, it is speculated that strains YBA_08 and F60C have the potential to contribute to furfural degradation in water and the production of furfuryl alcohol, ethanol, and FDCA in biorefinery processes.
Collapse
Affiliation(s)
- Hanyu Wang
- Institute of Resources and Geographic Information Technology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China; College of Life Science, Leshan Normal University, Leshan, Sichuan 614000, China; Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, College of Life Science, Leshan Normal University, Leshan, Sichuan 614000, China
| | - Qian Li
- Institute of Resources and Geographic Information Technology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Zhengyue Zhang
- Institute of Resources and Geographic Information Technology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Ellen Ayepa
- Institute of Resources and Geographic Information Technology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Quanju Xiang
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Xiumei Yu
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Ke Zhao
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Likou Zou
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Yunfu Gu
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Xi Li
- College of Landscape Architecture, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Qiang Chen
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Xiaoping Zhang
- Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Yaojun Yang
- College of Life Science, Leshan Normal University, Leshan, Sichuan 614000, China; Bamboo Diseases and Pests Control and Resources Development Key Laboratory of Sichuan Province, College of Life Science, Leshan Normal University, Leshan, Sichuan 614000, China
| | - Xuejiao Jin
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, Zhejiang 311300, China
| | - Huadong Yin
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China
| | - Z Lewis Liu
- The US Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Bioenergy Research Unit, 1815 N University Street, Peoria, IL 61604, USA
| | - Tianle Tang
- Key Laboratory of Tropical Transitional Medicine of Ministry of Education, Hainan Medical University, No.3 Xueyuan Road, Haikou, Hainan 571199, China.
| | - Beidong Liu
- State Key Laboratory of Subtropical Silviculture, School of Forestry and Biotechnology, Zhejiang A&F University, Lin'an, Hangzhou, Zhejiang 311300, China; Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, 413 90 Göteburg, Sweden.
| | - Menggen Ma
- Institute of Resources and Geographic Information Technology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China; Department of Applied Microbiology, College of Resources, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan 611130, China.
| |
Collapse
|
6
|
Kaushik A, Than T, Petela NJ, Voulgaris M, Percival C, Daniels P, Rafferty JB, Nasmyth KA, Hu B. Conformational dynamics of cohesin/Scc2 loading complex are regulated by Smc3 acetylation and ATP binding. Nat Commun 2023; 14:5929. [PMID: 37739959 PMCID: PMC10516938 DOI: 10.1038/s41467-023-41596-w] [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: 12/02/2022] [Accepted: 09/11/2023] [Indexed: 09/24/2023] Open
Abstract
The ring-shaped cohesin complex is a key player in sister chromatid cohesion, DNA repair, and gene transcription. The loading of cohesin to chromosomes requires the loader Scc2 and is regulated by ATP. This process is hindered by Smc3 acetylation. However, the molecular mechanism underlying this inhibition remains mysterious. Here, using Saccharomyces cerevisiae as a model system, we identify a novel configuration of Scc2 with pre-engaged cohesin and reveal dynamic conformations of the cohesin/Scc2 complex in the loading reaction. We demonstrate that Smc3 acetylation blocks the association of Scc2 with pre-engaged cohesin by impairing the interaction of Scc2 with Smc3's head. Lastly, we show that ATP binding induces the cohesin/Scc2 complex to clamp DNA by promoting the interaction between Scc2 and Smc3 coiled coil. Our results illuminate a dynamic reconfiguration of the cohesin/Scc2 complex during loading and indicate how Smc3 acetylation and ATP regulate this process.
Collapse
Affiliation(s)
- Aditi Kaushik
- The Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK
| | - Thane Than
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Naomi J Petela
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | | | - Charlotte Percival
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Peter Daniels
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - John B Rafferty
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Kim A Nasmyth
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Bin Hu
- The Institute of Medical Sciences, University of Aberdeen, Aberdeen, AB25 2ZD, UK.
| |
Collapse
|
7
|
Pobegalov G, Chu LY, Peters JM, Molodtsov MI. Single cohesin molecules generate force by two distinct mechanisms. Nat Commun 2023; 14:3946. [PMID: 37402740 DOI: 10.1038/s41467-023-39696-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/23/2023] [Indexed: 07/06/2023] Open
Abstract
Spatial organization of DNA is facilitated by cohesin protein complexes that move on DNA and extrude DNA loops. How cohesin works mechanistically as a molecular machine is poorly understood. Here, we measure mechanical forces generated by conformational changes in single cohesin molecules. We show that bending of SMC coiled coils is driven by random thermal fluctuations leading to a ~32 nm head-hinge displacement that resists forces up to 1 pN; ATPase head engagement occurs in a single step of ~10 nm and is driven by an ATP dependent head-head movement, resisting forces up to 15 pN. Our molecular dynamic simulations show that the energy of head engagement can be stored in a mechanically strained conformation of NIPBL and released during disengagement. These findings reveal how single cohesin molecules generate force by two distinct mechanisms. We present a model, which proposes how this ability may power different aspects of cohesin-DNA interaction.
Collapse
Affiliation(s)
- Georgii Pobegalov
- The Francis Crick Institute, London, NW1 1AT, UK
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK
| | - Lee-Ya Chu
- The Francis Crick Institute, London, NW1 1AT, UK
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Vienna, 1030, Austria
| | - Maxim I Molodtsov
- The Francis Crick Institute, London, NW1 1AT, UK.
- Department of Physics and Astronomy, University College London, London, WC1E 6BT, UK.
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter, Vienna, 1030, Austria.
| |
Collapse
|
8
|
Bürmann F, Löwe J. Structural biology of SMC complexes across the tree of life. Curr Opin Struct Biol 2023; 80:102598. [PMID: 37104976 PMCID: PMC10512200 DOI: 10.1016/j.sbi.2023.102598] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/20/2023] [Accepted: 03/26/2023] [Indexed: 04/29/2023]
Abstract
Structural maintenance of chromosomes (SMC) complexes guard and organize the three-dimensional structure of chromosomal DNA across the tree of life. Many SMC functions can be explained by an inherent motor activity that extrudes large DNA loops while the complexes move along their substrate. Here, we review recent structural insights into the architecture and conservation of these molecular machines, their interaction with DNA, and the conformational changes that are linked to their ATP hydrolysis cycle.
Collapse
Affiliation(s)
- Frank Bürmann
- MRC Laboratory of Molecular Biology, Structural Studies Division, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Structural Studies Division, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK.
| |
Collapse
|
9
|
Taschner M, Gruber S. DNA segment capture by Smc5/6 holocomplexes. Nat Struct Mol Biol 2023; 30:619-628. [PMID: 37012407 DOI: 10.1038/s41594-023-00956-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 03/01/2023] [Indexed: 04/05/2023]
Abstract
Three distinct structural maintenance of chromosomes (SMC) complexes facilitate chromosome folding and segregation in eukaryotes, presumably by DNA loop extrusion. How SMCs interact with DNA to extrude loops is not well understood. Among the SMC complexes, Smc5/6 has dedicated roles in DNA repair and preventing a buildup of aberrant DNA junctions. In the present study, we describe the reconstitution of ATP-dependent DNA loading by yeast Smc5/6 rings. Loading strictly requires the Nse5/6 subcomplex which opens the kleisin neck gate. We show that plasmid molecules are topologically entrapped in the kleisin and two SMC subcompartments, but not in the full SMC compartment. This is explained by the SMC compartment holding a looped DNA segment and by kleisin locking it in place when passing between the two flanks of the loop for neck-gate closure. Related segment capture events may provide the power stroke in subsequent DNA extrusion steps, possibly also in other SMC complexes, thus providing a unifying principle for DNA loading and extrusion.
Collapse
Affiliation(s)
- Michael Taschner
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Stephan Gruber
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
| |
Collapse
|
10
|
Martínez‐García B, Dyson S, Segura J, Ayats A, Cutts EE, Gutierrez‐Escribano P, Aragón L, Roca J. Condensin pinches a short negatively supercoiled DNA loop during each round of ATP usage. EMBO J 2023; 42:e111913. [PMID: 36533296 PMCID: PMC9890231 DOI: 10.15252/embj.2022111913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/23/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Condensin, an SMC (structural maintenance of chromosomes) protein complex, extrudes DNA loops using an ATP-dependent mechanism that remains to be elucidated. Here, we show how condensin activity alters the topology of the interacting DNA. High condensin concentrations restrain positive DNA supercoils. However, in experimental conditions of DNA loop extrusion, condensin restrains negative supercoils. Namely, following ATP-mediated loading onto DNA, each condensin complex constrains a DNA linking number difference (∆Lk) of -0.4. This ∆Lk increases to -0.8 during ATP binding and resets to -0.4 upon ATP hydrolysis. These changes in DNA topology do not involve DNA unwinding, do not spread outside the condensin-DNA complex and can occur in the absence of the condensin subunit Ycg1. These findings indicate that during ATP binding, a short DNA domain delimited by condensin is pinched into a negatively supercoiled loop. We propose that this loop is the feeding segment of DNA that is subsequently merged to enlarge an extruding loop. Such a "pinch and merge" mechanism implies that two DNA-binding sites produce the feeding loop, while a third site, plausibly involving Ycg1, might anchor the extruding loop.
Collapse
Affiliation(s)
| | - Sílvia Dyson
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Joana Segura
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Alba Ayats
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| | - Erin E Cutts
- DNA Motors GroupMRC London Institute of Medical Sciences (LMS)LondonUK
| | | | - Luís Aragón
- DNA Motors GroupMRC London Institute of Medical Sciences (LMS)LondonUK
| | - Joaquim Roca
- DNA Topology LabMolecular Biology Institute of Barcelona (IBMB), CSICBarcelonaSpain
| |
Collapse
|
11
|
Deep A, Gu Y, Gao YQ, Ego KM, Herzik MA, Zhou H, Corbett KD. The SMC-family Wadjet complex protects bacteria from plasmid transformation by recognition and cleavage of closed-circular DNA. Mol Cell 2022; 82:4145-4159.e7. [PMID: 36206765 PMCID: PMC9637719 DOI: 10.1016/j.molcel.2022.09.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/19/2022] [Accepted: 09/06/2022] [Indexed: 11/06/2022]
Abstract
Self versus non-self discrimination is a key element of innate and adaptive immunity across life. In bacteria, CRISPR-Cas and restriction-modification systems recognize non-self nucleic acids through their sequence and their methylation state, respectively. Here, we show that the Wadjet defense system recognizes DNA topology to protect its host against plasmid transformation. By combining cryoelectron microscopy with cross-linking mass spectrometry, we show that Wadjet forms a complex similar to the bacterial condensin complex MukBEF, with a novel nuclease subunit similar to a type II DNA topoisomerase. Wadjet specifically cleaves closed-circular DNA in a reaction requiring ATP hydrolysis by the structural maintenance of chromosome (SMC) ATPase subunit JetC, suggesting that the complex could use DNA loop extrusion to sense its substrate's topology, then specifically activate the nuclease subunit JetD to cleave plasmid DNA. Overall, our data reveal how bacteria have co-opted a DNA maintenance machine to specifically recognize and destroy foreign DNAs through topology sensing.
Collapse
Affiliation(s)
- Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yajie Gu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yong-Qi Gao
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kaori M Ego
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark A Herzik
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Huilin Zhou
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
12
|
Collier JE, Nasmyth KA. DNA passes through cohesin's hinge as well as its Smc3-kleisin interface. eLife 2022; 11:80310. [PMID: 36094369 PMCID: PMC9467508 DOI: 10.7554/elife.80310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/29/2022] [Indexed: 12/17/2022] Open
Abstract
The ring model proposes that sister chromatid cohesion is mediated by co-entrapment of sister DNAs inside a single tripartite cohesin ring. The model explains how Scc1 cleavage triggers anaphase but has hitherto only been rigorously tested using small circular mini-chromosomes in yeast, where covalently circularizing the ring by crosslinking its three interfaces induces catenation of individual and sister DNAs. If the model applies to real chromatids, then the ring must have a DNA entry gate essential for mitosis. Whether this is situated at the Smc3/Scc1 or Smc1/Smc3 hinge interface is an open question. We have previously demonstrated DNA entrapment by cohesin in vitro (Collier et al., 2020). Here we show that cohesin in fact possesses two DNA gates, one at the Smc3/Scc1 interface and a second at the Smc1/3 hinge. Unlike the Smc3/Scc1 interface, passage of DNAs through SMC hinges depends on both Scc2 and Scc3, a pair of regulatory subunits necessary for entrapment in vivo. This property together with the lethality caused by locking this interface but not that between Smc3 and Scc1 in vivo suggests that passage of DNAs through the hinge is essential for building sister chromatid cohesion. Passage of DNAs through the Smc3/Scc1 interface is necessary for cohesin’s separase-independent release from chromosomes and may therefore largely serve as an exit gate.
Collapse
Affiliation(s)
- James E Collier
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Kim A Nasmyth
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
13
|
Bock FP, Liu HW, Anchimiuk A, Diebold-Durand ML, Gruber S. A joint-ParB interface promotes Smc DNA recruitment. Cell Rep 2022; 40:111273. [PMID: 36044845 PMCID: PMC9449133 DOI: 10.1016/j.celrep.2022.111273] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 06/21/2022] [Accepted: 08/05/2022] [Indexed: 12/14/2022] Open
Abstract
Chromosomes readily unlink and segregate to daughter cells during cell division, highlighting a remarkable ability of cells to organize long DNA molecules. SMC complexes promote DNA organization by loop extrusion. In most bacteria, chromosome folding initiates at dedicated start sites marked by the ParB/parS partition complexes. Whether SMC complexes recognize a specific DNA structure in the partition complex or a protein component is unclear. By replacing genes in Bacillus subtilis with orthologous sequences from Streptococcus pneumoniae, we show that the three subunits of the bacterial Smc complex together with the ParB protein form a functional module that can organize and segregate foreign chromosomes. Using chimeric proteins and chemical cross-linking, we find that ParB directly binds the Smc subunit. We map an interface to the Smc joint and the ParB CTP-binding domain. Structure prediction indicates how the ParB clamp presents DNA to the Smc complex, presumably to initiate DNA loop extrusion. The bacterial DNA-binding protein ParB interacts with the condensin-like Smc-ScpAB Genetic mapping and structure predictions reveal an Smc joint-ParB binding interface Mutating the binding interface hampers Smc recruitment but not other ParB functions ParB and Smc-ScpAB form a transplantable unit for chromosome segregation in bacteria
Collapse
Affiliation(s)
- Florian P Bock
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015 Lausanne, Switzerland
| | - Hon Wing Liu
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015 Lausanne, Switzerland
| | - Anna Anchimiuk
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015 Lausanne, Switzerland
| | - Marie-Laure Diebold-Durand
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015 Lausanne, Switzerland
| | - Stephan Gruber
- Department of Fundamental Microbiology (DMF), Faculty of Biology and Medicine (FBM), University of Lausanne, 1015 Lausanne, Switzerland.
| |
Collapse
|
14
|
Cryo-EM structure of DNA-bound Smc5/6 reveals DNA clamping enabled by multi-subunit conformational changes. Proc Natl Acad Sci U S A 2022; 119:e2202799119. [PMID: 35648833 PMCID: PMC9191643 DOI: 10.1073/pnas.2202799119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Smc5/6 complex plays multiple roles in DNA replication and repair. Its genome-protecting functions rely on its interaction with DNA; however, how this complex engages DNA is poorly understood. We report on a cryogenic electron microscopy structure of DNA-bound budding yeast Smc5/6 complex, revealing that its subunits form a clamp to encircle a double-helical DNA. We define the multi-subunit interactions forming the DNA clamp and the DNA binding sites distributed among subunits. We identify subunit transformations upon DNA capture and functional effects conferred by its multiple DNA contact sites. Our findings, in conjunction with studies on other structural maintenance of chromosomes (SMC) complexes, suggest a common SMC DNA-clamp mechanism with individual complex specific features that enable diverse genome organization and protection functions by SMC family complexes. Structural maintenance of chromosomes (SMC) complexes are essential for chromatin organization and functions throughout the cell cycle. The cohesin and condensin SMCs fold and tether DNA, while Smc5/6 directly promotes DNA replication and repair. The functions of SMCs rely on their abilities to engage DNA, but how Smc5/6 binds and translocates on DNA remains largely unknown. Here, we present a 3.8 Å cryogenic electron microscopy (cryo-EM) structure of DNA-bound Saccharomyces cerevisiae Smc5/6 complex containing five of its core subunits, including Smc5, Smc6, and the Nse1-3-4 subcomplex. Intricate interactions among these subunits support the formation of a clamp that encircles the DNA double helix. The positively charged inner surface of the clamp contacts DNA in a nonsequence-specific manner involving numerous DNA binding residues from four subunits. The DNA duplex is held up by Smc5 and 6 head regions and positioned between their coiled-coil arm regions, reflecting an engaged-head and open-arm configuration. The Nse3 subunit secures the DNA from above, while the hook-shaped Nse4 kleisin forms a scaffold connecting DNA and all other subunits. The Smc5/6 DNA clamp shares similarities with DNA-clamps formed by other SMCs but also exhibits differences that reflect its unique functions. Mapping cross-linking mass spectrometry data derived from DNA-free Smc5/6 to the DNA-bound Smc5/6 structure identifies multi-subunit conformational changes that enable DNA capture. Finally, mutational data from cells reveal distinct DNA binding contributions from each subunit to Smc5/6 chromatin association and cell fitness. In summary, our integrative study illuminates how a unique SMC complex engages DNA in supporting genome regulation.
Collapse
|
15
|
Shaltiel IA, Datta S, Lecomte L, Hassler M, Kschonsak M, Bravo S, Stober C, Ormanns J, Eustermann S, Haering CH. A hold-and-feed mechanism drives directional DNA loop extrusion by condensin. Science 2022; 376:1087-1094. [PMID: 35653469 DOI: 10.1126/science.abm4012] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Structural maintenance of chromosomes (SMC) protein complexes structure genomes by extruding DNA loops, but the molecular mechanism that underlies their activity has remained unknown. We show that the active condensin complex entraps the bases of a DNA loop transiently in two separate chambers. Single-molecule imaging and cryo-electron microscopy suggest a putative power-stroke movement at the first chamber that feeds DNA into the SMC-kleisin ring upon adenosine triphosphate binding, whereas the second chamber holds on upstream of the same DNA double helix. Unlocking the strict separation of "motor" and "anchor" chambers turns condensin from a one-sided into a bidirectional DNA loop extruder. We conclude that the orientation of two topologically bound DNA segments during the SMC reaction cycle determines the directionality of DNA loop extrusion.
Collapse
Affiliation(s)
- Indra A Shaltiel
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Sumanjit Datta
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Léa Lecomte
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Markus Hassler
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Marc Kschonsak
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Sol Bravo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Catherine Stober
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Jenny Ormanns
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany
| | | | - Christian H Haering
- Department of Biochemistry and Cell Biology, Julius Maximilian University of Würzburg, 97074 Würzburg, Germany.,Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Structural and Computational Biology Unit, EMBL, 69117 Heidelberg, Germany
| |
Collapse
|
16
|
A walk through the SMC cycle: From catching DNAs to shaping the genome. Mol Cell 2022; 82:1616-1630. [PMID: 35477004 DOI: 10.1016/j.molcel.2022.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 02/02/2022] [Accepted: 04/04/2022] [Indexed: 12/16/2022]
Abstract
SMC protein complexes are molecular machines that provide structure to chromosomes. These complexes bridge DNA elements and by doing so build DNA loops in cis and hold together the sister chromatids in trans. We discuss how drastic conformational changes allow SMC complexes to build such intricate DNA structures. The tight regulation of these complexes controls fundamental chromosomal processes such as transcription, recombination, repair, and mitosis.
Collapse
|