SMC Proteins & Chromosome Dynamics

The Gruber lab investigates conserved molecular machines that ensure the integrity, propagation, and expression of genetic information. By all means.

  • How are genomes organized in the cell ?
  • How are chromosomes segregated during cell division ?
  • How is DNA damage repaired ?

We are part of the Department of Fundamental Microbiology (DMF) at the Faculty of Biology and Medicine, the University of Lausanne. Find out who we are and what we do. Follow us .

Electron micrograph showing part of a decondensed mitotic chromosome. CIL: 11023

In science, truth always wins.‘ Max Perutz

The two most powerful warriors are patience and time.‘ Leo Tolstoy

There is no substitute for being first‘ John F Marko


DNA Organization, Dynamics & Repair

Folding chromosomes by DNA loop extrusion

Cells organize and compact the long and flexible DNA molecules within chromosomes to precisely control gene expression patterns, to support DNA repair processes and DNA recombination events, and to faithfully segregate chromosomes during cell division. What determines chromosome superstructure and how it impacts upon genome expression and genome maintenance are major open questions in biology. We aim to elucidate fundamental principles of chromosome folding by studying microbial model organisms including the Gram-positive bacterium Bacillus subtilis and budding yeast Saccharomyces cerevisiae. 

SMC proteins & DNA loop extrusion

Dynamic SMC architecture

Our work focuses on two widely distributed factors in chromosome organization: SMC protein complexes and ParABS systems. SMC complexes form multi-subunit ATPases with a characteristic ring topology. They organize DNA as genome linkers by clamping together pairs of chromosomal DNA segments. To uncover how they bring together the “right” pairs of DNA double helices, we investigate how SMC complexes interact with DNA and chromosomes. The emerging view is that DNA loop extrusion by SMC DNA motors plays the key role in the remarkable process of chromosome organization. In bacteria, SMC complexes load onto chromosomes at defined entry sites — parS sites — and then translocate onto flanking DNA helping to shape entire bacterial chromosomes. We want to understand how local SMC loading and subsequent DNA translocation brings about global chromosome folding.

ParABS & cellular regulation

ParB CTPase self-loading at a parS site.

ParABS systems promote chromosome segregation and plasmid maintenance in many bacteria and some archaea. It also supports additional regulatory functions in the cell. ParABS systems work by ParB protein binding to centromeric parS sequences to form large nucleoprotein complexes that act in concert with specific ATPases, ParA and Smc, to partition plasmid and chromosome copies. We have recently discovered that ParB proteins are enzymes — the first known CTP hydrolases — which form DNA sliding clamps that self-load onto parS DNA. We are particularly interested how ParB CTP binding and hydrolysis act together with ParA and Smc ATPases to promote chromosome organization and segregation in bacteria.

Our approach

Knowledge of the architecture and structure of macromolecular assemblies is often a prerequisite for a basic mechanistic understanding. We integrate genetics, molecular & cell biology and biochemistry with structural biology approaches to reveal the molecular basis for protein function and cellular activity.

We investigate protein-DNA complexes and DNA organization in vitro using an array of biophysical techniques and structural biology and in vivo for example by ChIP-Seq, Hi-C, directed or random mutagenesis and site-specific cross-linking. Bacillus subtilis develops natural competence under starvation and can readily be genetically manipulated, supporting easy and high-throughput allelic replacements.

New focus

In relatively new lines of investigation, we are focusing on the roles of SMC and SMC-like proteins (Rad50, RecN and the Smc5/6 complex) in the maintenance of DNA integrity in bacteria and eukaryotes.



Hammam Antar



2017-2019 – M. Sc. Immunology, Microbiology & Infectious Diseases (IMD) – University of Grenoble Alpes, France

Joe Dickinson



2020-2022 – M. Sc. Molecular Life Sciences – University of Lausanne, Switzerland

Ophélie Gosselin



2017-2019 – M. Sc. Biochemistry, Molecular and Cellular Biology – UC Louvain, Belgium

Stephan Gruber


Short CV

stephan gruber unil ch

OrcID, ResearchGate, Google Scholar

Maya Houmel



2018-2020 – M. Sc. Genetics,  Magistère Européen de Génétique, University of Paris, France

Franziska Kemter – DFG Postdoc



2014-2019 – Ph. D. and Postdoc, Chromosome Biology – Waldminghaus lab, SYNMICRO, Philipps-University Marburg, Germany
2012-2014 – M. Sc. Molecular and Cellular Biology – Philipps-University Marburg, Germany

Yan Li[a]

2015-2019 – Ph. D. , Panne lab, EMBL Grenoble, France
2010-2013 – M. Sc. Structural Biology – University of the Chinese Academy of Sciences, Shanghai, China

Hon-Wing Liu – EMBO Postdoc



2015-2020 – Ph. D. , Uhlmann lab, The Francis Crick Institute, London, UK
2011-2015 – MA M. Sc. Biochemistry – University of Cambridge, UK

Nicolas Pellaton



2020- 2021 – M. Sc. student, University of Lausanne
2017-2020 – B. Sc. Biology, University of Lausanne, Switzerland

Florian Roisné-Hamelin



2016-2021 – Ph. D., Marcand lab,  Institut de Biologie François Jacob, CEA, Paris, France

2014-2016 – M. Sc. Genetics & Cell Biology- University of Lyon 1, France

Michael Taschner – Research scientist



2010-2017 – Postdoc – Lorentzen lab, Max Planck Institute of Biochemistry, Munich, Germany
2005-2009 – Ph. D. Biochemistry – Svejstrup lab, UCL, UK
2000-2004 – Diploma Biology – University of Vienna, Austria

Former lab members

Anna Anchimiuk, PhD student, now @ Roche, Switzerland

Alrun Basfeld, Intern, now @ WuXi Biologics, Leverkusen, Germany

Mélanie Beraud, Postdoctoral fellow, now senior technician @ Université de Mons, Mons, Belgium

Martin Blettinger, Technician, now @ Hexal Sandoz, Munich, Germany

Florian Bock, PhD student, now @ Venning lab, Lausanne, Switzerland

Frank Bürmann, PhD student, now Postdoc @ MRC-LMB Cambridge, UK

Marie-Laure Diebold-Durand, Postdoctoral fellow, now @IGBMC Strasbourg, France

Alexandre Durand, Postdoctoral fellow, now EM Facility Manager – Inserm @IGBMC Strasbourg, France

Victor Gimenez-Oya, Postdoctoral fellow, now @ LMU Munich, Germany

Daniel Meyer, Technician, now @ Max Planck Institute for Quantum Optics, Munich, Germany

Anita Minnen, PhD student, now Postdoc @ Max Planck Institute of Biochemistry, Munich, Germany

Laura Ruiz Avila, Postdoctoral fellow, now @ Extedo, Munich, Germany

Jae Shin, Postdoc, now Senior Researcher @ NanoLund, Sweden

Young-Min Soh, Postdoctoral fellow, now fellow @ NIH, US

Chris Toseland, Postdoctoral fellow, now group leader @ University of Kent, UK

Roberto Vazquez Nunez, PhD student, now Postdoctoral fellow @ NIH, US

Larissa Wilhelm, PhD student, now @ Novartis, Vienna, Austria



  • Roberts D. M., Anchimiuk A., Kloosterman T. G., Murray H., Wu L. J, Gruber S., Errington J.*, 2021. Chromosome remodelling by SMC/Condensin in B. subtilis is regulated by Soj/ParA during growth and sporulation.
    preprint [BioRxiv]


  • Bock F. P., Liu H. W., Anchimiuk A., Diebold-Durand M.-L., Gruber S.*, 2022. A joint-ParB interface promotes Smc DNA recruitment.
    Cell Reports
    Vol 40, Issue 9 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Tisma M., Panoukidou M., Antar H., Soh Y.-M., Barth R., Pradhan B., van der Torre J., Michieletto D., Gruber S., Dekker C.*, 2022. ParB proteins can bypass DNA-bound roadblocks by dimer-dimer recruitment.
    Science Advances
    Vol 8, Issue 26 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Nomidis S.S., Carlon E., Gruber S., Marko J. F.*, 2022. DNA tension-modulated translocation and loop extrusion by SMC complexes revealed by molecular dynamics simulations.
    Nucleic acids research
    gkac268 [Pubmed] [DOI]
    preprint [BioRxiv]


  • Antar H.°, Soh Y.-M.°, Zamuner S., Bock F. P., Anchimiuk A., De Los Rios P., Gruber S.*, 2021. Relief of ParB autoinhibition by parS DNA catalysis and ParB recycling by CTP hydrolysis promote bacterial centromere assembly.
    Science Advances
    Vol 7, Issue 41 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Taschner M., Basquin J., Steigenberger B., Schaefer I., Soh Y.-M., Basquin C., Lorentzen E., Räschle M., Scheltema R. A., Gruber S.*, 2021. Nse5/6 inhibits the Smc5/6 ATPase and modulates DNA substrate binding.
    EMBO Journal
    e107807 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Anchimiuk A., Lioy V. S., Minnen A., Boccard F., Gruber S.*, 2021. A low Smc flux avoids collisions and facilitates chromosome organization in B. subtilis.
    65467 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Gallay C.°, Sanselicio S.°, Anderson M. E.,  Soh Y.-M., Liu X., Stamsas G. A., Pelliciari S., van Raaphorst R., Dénéréaz J., Kjos M., Murray H., Gruber S., Grossman A. D., Veening J.-W.*, 2021. CcrZ is a pneumococcal spatiotemporal cell cycle regulator that interacts with FtsZ and controls DNA replication.
    Nature Microbiology
    021-00949-1 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Vazquez Nunez R. J.°, Polyhach Y.°, Soh Y.-M., Jeschke G., Gruber S.*, 2021. Gradual opening of Smc arms in prokaryotic condensin.
    Cell Reports
    35(4) 109051 [Pubmed] [DOI]
    preprint [BioRxiv]


  • Soh Y.-M., Basquin J., Gruber S.*, 2020. A rod conformation of the Pyrococcus furiosus Rad50 coiled coil.
    prot.26005 [Pubmed] [DOI] [PDB: 6ZFF]
    preprint [BioRxiv]
  • Metwaly G., Wu Y., Peplowska K., Röhrl J., Soh Y.-M., Bürmann F., Gruber S., Storchova Z.*, 2020. Phospho-regulation of the Shugoshin-Condensin interaction at the centromere in budding yeast.
    PLOS Genetics
    16(8) [Pubmed] [DOI]
    preprint [BioRxiv]
  • Jeon J.-H., Lee H.-S., Shin H.-C., Kwak M.-J., Kim Y.-G., Gruber S. and Oh B.-H.*, 2020. Evidence for binary Smc complexes lacking kite subunits in archaea.
    7(2) [Pubmed] [DOI]
  • Prassler J., Simon F., Ecke M., Gruber S. and Gerisch G.* 2020. Decision making in phagocytosis.
    1246:71-81 [Pubmed] [DOI] [PDF]


  • Soh Y.-M., Davidson I. F., Zamuner S., Basquin J., Taschner M., Bock F. P., Veening J.-W., De Los Rios P., Peters J.-M., Gruber S.*, 2019. Self-organization of parS centromeres by the ParB CTP hydrolase.
    360(6469) p. 1129-1133 [Pubmed] [DOI] [Free] [PDB: 6SDK] [PDF] [F1000_recommendations] [Perspective by Barbara Funnell]
  • Vazquez Nunez R.°, Ruiz Avila L. B.°, Gruber S.*, 2019. Transient DNA occupancy of the SMC interarm space in prokaryotic condensin.
    Molecular Cell
    75(5) p. 1-15 [Pubmed] [DOI] [Free full-text] [Preview by Tomoko Nishiyama]
    preprint [BioRxiv]
  • Marko J. F.*, De Los Rios P., Barducci A., Gruber S., 2019. DNA-segment-capture model for loop extrusion by structural maintenance of chromosome (SMC) protein complexes.
    Nucleic Acids Research

    gkz497 [Pubmed] [DOI]
    preprint [BioRxiv]
  • Diebold-Durand M.-L., Bürmann F., Gruber S.*, 2019. High-throughput allelic replacement screening in Bacillus subtilis.
    Methods in Molecular Biology

    2004 p. 49-61 [Pubmed] [DOI] [PDF]


  • Pfeiffer F., Zamora-Lagos M.-A., Blettinger M., Yeroslavic A., Dahl A., Gruber S.*, Habermann B. H.*, 2018. The complete and fully assembled genome sequence of Aeromonas salmonicida subsp. pectinolytica and its comparative analysis with other Aeromonas species: investigation of the mobilome in environmental and pathogenic strains.
    BMC Genomics
    19(1):20 [Pubmed] [DOI]
  • Gruber S., 2018. SMC complexes sweeping through the chromosome: Going with the flow and against the tide.
    Current Opinion in Microbiology
    42:96-103 [Pubmed] [DOI] [PDF]
  • Stockmar I., Feddersen H., Cramer K., Gruber S., Jung K., Bramkamp M.*, Shin J. Y.* 2018. Optimization of sample preparation and green color imaging using the mNeonGreen fluorescent protein in bacterial cells for photoactivated localization microscopy.
    Scientific Reports
    8(1): 10137 [Pubmed] [DOI]


  • Diebold-Durand M.-L.°, Lee H.°, Ruiz Avila L.°, Noh H., Shin H.-C., Im H., Bock F. P., Bürmann F., Durand A., Basfeld A., Ham S., Basquin J., Oh B.-H.*, Gruber S.*, 2017. Structure of full-length SMC and rearrangements required for chromosome organization.
    Molecular Cell
    67(2) p. 334-347 [DOI] [Web of Science] [Pubmed] [PDB: 5NMO, 5NNV]
  • Bürmann F., Basfeld A., Vazquez Nunez R., Diebold-Durand M.-L., Wilhelm L., Gruber S.*, 2017. Tuned SMC arms drive chromosomal loading of prokaryotic condensin.
    Molecular Cell
    65(5) p. 861-872 [DOI] [Web of Science] [Pubmed] [F1000 recommendation]
  • Gruber S., 2017. Shaping Chromosomes by DNA Capture and Release: Gating the SMC Rings.
    Current Opinion in Cell Biology
    46:87-93 [DOI] [Web of Science] [Pubmed] [PDF]
  • Wilhelm L., Gruber S.*, 2017. A Chromosome Co-Entrapment Assay to Study Topological Protein–DNA Interactions.
    Methods in Molecular Biology
    1624 p. 117-126 [DOI] [Web of Science] [Pubmed] [PDF]. An updated version of the protocol (using agarose microbeads instead of agarose plugs) is available here: [DOI].


  • Minnen A.°, Bürmann F.°, Wilhelm L., Anchimiuk A., Diebold-Durand M.-L., Gruber S.*, 2016. Control of Smc Coiled Coil Architecture by the ATPase Heads Facilitates Targeting to Chromosomal ParB/parS and Release onto Flanking DNA.
    Cell Reports
    14(8) p. 2003-2016 [DOI[Web of Science[Pubmed]
  • Haering C. H., Gruber S., 2016. SnapShot: SMC Protein Complexes Part I.
    164(1-2) p. 326-6.e1 [DOI[Web of Science[Pubmed]
  • Haering C. H., Gruber S., 2016. SnapShot: SMC Protein Complexes Part II.
    164(4) p. 818.e1 [DOI[Web of Science[Pubmed]
  • Wilhelm L., Gruber S., 2016. Chromosom in Schleifen: SMC-Komplexe als molekulare Kabelbinder? 
    22(4) p. 356-358 [DOI] [PDF]


  • Soh Y.-M.°, Bürmann F.°, Shin H. C., Oda T., Jin K. S., Toseland C. P., Kim C., Lee H., Kim S. J., Kong M. S., Durand-Diebold M.-L., Kim Y. G., Kim H. M., Lee N. K., Sato M., Oh B. H.*, Gruber S.*, 2015. Molecular basis for SMC rod formation and its dissolution upon DNA binding. 
    Molecular Cell
    57(2) p. 290-303 [DOI[Web of Science[Pubmed]
  • Wilhelm L., Bürmann F., Minnen A., Shin H. C., Toseland C. P., Oh B.-H., Gruber S.*, 2015. SMC condensin entraps chromosomal DNA by an ATP hydrolysis dependent loading mechanism in Bacillus subtilis.
    4:e06659 [DOI[Web of Science[Pubmed]
  • Palecek J. J.*, Gruber S.*, 2015. Kite Proteins: a Superfamily of SMC/Kleisin Partners Conserved Across Bacteria, Archaea, and Eukaryotes.
    23(12) p. 2183-2190. [DOI[Web of Science[Pubmed]
  • Kang H.A., Shin H.C., Kalantzi A.S., Toseland C.P., Kim H. M., Gruber S., Peraro M. D., Oh B.-H.*, 2015. Crystal structure of Hop2-Mnd1 and mechanistic insights into its role in meiotic recombination.
    Nucleic Acids Research
    43(7) p. 3841-3856 [DOI[Web of Science[Pubmed]
  • Attaiech L., Minnen A., Kjos M., Gruber S., Veening J.-W.*, 2015. The ParB-parS Chromosome Segregation System Modulates Competence Development in Streptococcus pneumoniae.
    6(4) p. e00662 [DOI[Web of Science[Pubmed]
  • Bürmann F., Gruber S., 2015. SMC condensin: promoting cohesion of replicon arms.
    Nature Structural & Molecular Biology
    22(9) p. 653-655 [DOI[Web of Science[Pubmed] [PDF] [PDB: 3ZGX]


  • Gruber S.*, Veening J.-W., Bach J., Blettinger M., Bramkamp M., Errington J.*, 2014. Interlinked sister chromosomes arise in the absence of condensin during fast replication in B. subtilis.
    Current Biology
    24(3) p. 293-298 [DOI[Web of Science[Pubmed]
  • Gligoris T. G., Scheinost J. C., Bürmann F., Petela N., Chan K. L., Uluocak P., Beckouët F., Gruber S., Nasmyth K.*, Löwe J.*, 2014. Closing the cohesin ring: structure and function of its Smc3-kleisin interface.
    346(6212) p. 963-967 [DOI[Web of Science[Pubmed]
  • Gruber S., 2014. Multilayer chromosome organization through DNA bending, bridging and extrusion.
    Current Opinion In Microbiology
    22 p. 102-110 [DOI[Web of Science[Pubmed]


  • Bürmann F.°, Shin H. C.°, Basquin J., Soh Y.-M., Giménez-Oya V., Kim Y. G., Oh B.-H.*, Gruber S.*, 2013. An asymmetric SMC-kleisin bridge in prokaryotic condensin.
    Nature Structural & Molecular Biology
    20(3) p. 371-379 [DOI[Web of Science[Pubmed] [PDF]


  • Gruber S., 2011. MukBEF on the march: taking over chromosome organization in bacteria?
    Molecular Microbiology
    81(4) p. 855-859 [DOI[Web of Science[Pubmed]
  • Minnen A., Attaiech L., Thon M., Gruber S.*, Veening J.-W.*, 2011. SMC is recruited to oriC by ParB and promotes chromosome segregation in Streptococcus pneumoniae.
    Molecular Microbiology
    81(3) p. 676-688 [DOI[Web of Science[Pubmed]


  • Gruber S., Errington J.*, 2009. Recruitment of condensin to replication origin regions by ParB/SpoOJ promotes chromosome segregation in B. subtilis.
    137(4) p. 685-696 [DOI[Web of Science[Pubmed]


  • Gruber S., Arumugam P., Katou Y., Kuglitsch D., Helmhart W., Shirahige K., Nasmyth K.*, 2006. Evidence that loading of cohesin onto chromosomes involves opening of its SMC hinge.
    127(3) p. 523-537 [DOI[Web of Science[Pubmed]
  • Arumugam P., Nishino T., Haering C.H., Gruber S., Nasmyth K.*, 2006. Cohesin’s ATPase activity is stimulated by the C-terminal Winged-Helix domain of its kleisin subunit.
    Current Biology
    16(20) p. 1998-2008 [DOI[Web of Science[Pubmed]


  • Riedel C. G.*, Gregan J., Gruber S., Nasmyth K., 2004. Is chromatin remodeling required to build sister-chromatid cohesion?
    Trends In Biochemical Sciences
    29(8) p. 389-392 [DOI[Web of Science[Pubmed] [PDF]


  • Gruber S.°, Haering C. H.°, Nasmyth K.*, 2003. Chromosomal cohesin forms a ring.
    112(6) p. 765-777 [DOI] [Web of Science[Pubmed]
  • Arumugam P., Gruber S., Tanaka K., Haering C. H., Mechtler K., Nasmyth K.*, 2003. ATP hydrolysis is required for cohesin’s association with chromosomes.
    Current Biology
    13(22) p. 1941-1953 [DOI] [Web of Science[Pubmed]
  • Buonomo S. B., Rabitsch K. P., Fuchs J., Gruber S., Sullivan M., Uhlmann F., Petronczki M., Tóth A., Nasmyth K.*, 2003. Division of the nucleolus and its release of CDC14 during anaphase of meiosis I depends on separase, SPO12, and SLK19.
    Developmental Cell
    4(5) p. 727-739 [DOI] [Web of Science[Pubmed]