Stephan Gruber
@gruberlab.bsky.social
Microbiologist | Biochemist | Structural Biologist, Lausanne 🇨🇭 | Studying molecular machines (SMC, ParB, Wadjet, Lamassu & more) in Genome Integrity & Nucleic Acid Immunity.
🔬 Lab homepage: wp.unil.ch/gruberlab
🔬 Lab homepage: wp.unil.ch/gruberlab
Pinned
Stephan Gruber
@gruberlab.bsky.social
· Nov 25
The SMC Hinge is a Selective Gate for Obstacle Bypass - Nature Communications
SMC complexes are ring-shaped motors that fold DNA by extruding loops, but how they navigate large DNA obstacles is unclear. Here, Liu et al., show that SMC complexes bypass obstacles by threading obs...
doi.org
The hinge bypass gate paper is finally out! doi.org/10.1038/s414...
We show how loop-extruding SMC complexes can maintain DNA entrapment while bypassing obstacles on DNA — including transcription machinery & potentially other SMCs.
A lucky convergence of 3 projects lead to the initial discovery!
We show how loop-extruding SMC complexes can maintain DNA entrapment while bypassing obstacles on DNA — including transcription machinery & potentially other SMCs.
A lucky convergence of 3 projects lead to the initial discovery!
Reposted by Stephan Gruber
JOB ALERT: Operations Director (DCI–Lausanne).
The DCI, a joint initiative of EPFL, UNIL, UNIGE and UNIBE, is recruiting an Operations Director to lead the cryo-EM facility in Lausanne.
📩 Questions: CEO of the DCI: @chgenoud.bsky.social
🔗 Apply here: careers.epfl.ch/job/Lausanne...
The DCI, a joint initiative of EPFL, UNIL, UNIGE and UNIBE, is recruiting an Operations Director to lead the cryo-EM facility in Lausanne.
📩 Questions: CEO of the DCI: @chgenoud.bsky.social
🔗 Apply here: careers.epfl.ch/job/Lausanne...
December 17, 2025 at 12:00 PM
JOB ALERT: Operations Director (DCI–Lausanne).
The DCI, a joint initiative of EPFL, UNIL, UNIGE and UNIBE, is recruiting an Operations Director to lead the cryo-EM facility in Lausanne.
📩 Questions: CEO of the DCI: @chgenoud.bsky.social
🔗 Apply here: careers.epfl.ch/job/Lausanne...
The DCI, a joint initiative of EPFL, UNIL, UNIGE and UNIBE, is recruiting an Operations Director to lead the cryo-EM facility in Lausanne.
📩 Questions: CEO of the DCI: @chgenoud.bsky.social
🔗 Apply here: careers.epfl.ch/job/Lausanne...
Reposted by Stephan Gruber
@science.org Chromatin buffers torsional stress during transcription | Science www.science.org/doi/10.1126/...
Chromatin buffers torsional stress during transcription
During eukaryotic transcription, Pol II must overcome nucleosome obstacles and, because of DNA’s helical structure, must also rotate relative to DNA, generating torsional stress. However, there is lim...
www.science.org
December 19, 2025 at 10:31 PM
@science.org Chromatin buffers torsional stress during transcription | Science www.science.org/doi/10.1126/...
Reposted by Stephan Gruber
Verspätungen 2025 an über 100 europäischen Bahnhöfen: Sogar italienische Züge sind pünktlicher als deutsche... 🙈
Quelle: chuuchuu.com/2025wrapped
Quelle: chuuchuu.com/2025wrapped
December 19, 2025 at 1:49 PM
Verspätungen 2025 an über 100 europäischen Bahnhöfen: Sogar italienische Züge sind pünktlicher als deutsche... 🙈
Quelle: chuuchuu.com/2025wrapped
Quelle: chuuchuu.com/2025wrapped
Reposted by Stephan Gruber
Coupled to the general budget cuts by both the canton and federal government to our University (and it's happening at most institutes in Switzerland), this would be really bad. The project funding scheme is really the best thing about Swiss science, so please don't touch this!
The SNSF is considering restrictions for its Project funding. Goal: to ensure the quality of evaluation & stable success rates despite an increasing number of applications and limited funding. The final decision will be made in January 2026.
👉 buff.ly/iGOCf7R
#research #science
👉 buff.ly/iGOCf7R
#research #science
Project funding restrictions envisaged
The SNSF is responding to increased demand from researchers in order to ensure evaluation quality and stabilise success rates.
buff.ly
December 18, 2025 at 10:40 AM
Coupled to the general budget cuts by both the canton and federal government to our University (and it's happening at most institutes in Switzerland), this would be really bad. The project funding scheme is really the best thing about Swiss science, so please don't touch this!
Reposted by Stephan Gruber
Dana-Farber Cancer Institute Agrees to Pay $15 Million to Settle Fraud Allegations Related to Scientific Research Grants. The relator [Sholto David] will receive $2,625,000 under today’s settlement.
www.justice.gov/usao-ma/pr/d...
www.justice.gov/usao-ma/pr/d...
Dana-Farber Cancer Institute Agrees to Pay $15 Million to Settle Fraud Allegations Related to Scientific Research Grants
BOSTON – Dana-Farber Cancer Institute, Inc. (Dana-Farber) has agreed to pay $15 million to resolve allegations that, between 2014 and 2024, it made materially false statements and certifications relat...
www.justice.gov
December 16, 2025 at 9:32 PM
Dana-Farber Cancer Institute Agrees to Pay $15 Million to Settle Fraud Allegations Related to Scientific Research Grants. The relator [Sholto David] will receive $2,625,000 under today’s settlement.
www.justice.gov/usao-ma/pr/d...
www.justice.gov/usao-ma/pr/d...
Reposted by Stephan Gruber
Online Now: The Ppl protein senses 3′-hydroxyl DNA overhangs and NTP depletion to halt phage infection Online now:
The Ppl protein senses 3′-hydroxyl DNA overhangs and NTP depletion to halt phage infection
Xu et al. reveal that the Ppl defense system protects bacteria from phages by acting as a “double-check” security system. It requires two simultaneous phage-induced stresses to activate, a sophisticated mechanism that ensures effective immunity while preventing premature abortive infection.
dlvr.it
December 3, 2025 at 11:57 PM
Online Now: The Ppl protein senses 3′-hydroxyl DNA overhangs and NTP depletion to halt phage infection Online now:
Reposted by Stephan Gruber
New online: DNA topoisomerase I acts as supercoiling sensor for bacterial transcription elongation
DNA topoisomerase I acts as supercoiling sensor for bacterial transcription elongation
Nature Structural & Molecular Biology, Published online: 01 December 2025; doi:10.1038/s41594-025-01703-5Vidmar et al. use cryo-EM to reveal how bacterial RNA polymerase (RNAP) and topoisomerase I (TopoI) cooperate. TopoI switches conformation, senses DNA supercoils near RNAP and relaxes them. Mutations disrupting this process alter bacterial motility and operon polarity.
go.nature.com
December 1, 2025 at 6:09 PM
New online: DNA topoisomerase I acts as supercoiling sensor for bacterial transcription elongation
Reposted by Stephan Gruber
Really looking forward to hosting Elisabeth on Monday Dec 1 at @fbm-unil.bsky.social @unil.bsky.social for our BIG seminar: 12.15 in Genopode C (note change of room). Open to everyone.
I will be giving several talks this coming week at universities in Switzerland: Lausanne, Neuchâtel, Basel, and Bern. Hope to see some of you there!
November 30, 2025 at 9:50 AM
Really looking forward to hosting Elisabeth on Monday Dec 1 at @fbm-unil.bsky.social @unil.bsky.social for our BIG seminar: 12.15 in Genopode C (note change of room). Open to everyone.
The hinge bypass gate paper is finally out! doi.org/10.1038/s414...
We show how loop-extruding SMC complexes can maintain DNA entrapment while bypassing obstacles on DNA — including transcription machinery & potentially other SMCs.
A lucky convergence of 3 projects lead to the initial discovery!
We show how loop-extruding SMC complexes can maintain DNA entrapment while bypassing obstacles on DNA — including transcription machinery & potentially other SMCs.
A lucky convergence of 3 projects lead to the initial discovery!
The SMC Hinge is a Selective Gate for Obstacle Bypass - Nature Communications
SMC complexes are ring-shaped motors that fold DNA by extruding loops, but how they navigate large DNA obstacles is unclear. Here, Liu et al., show that SMC complexes bypass obstacles by threading obs...
doi.org
November 25, 2025 at 3:26 PM
The hinge bypass gate paper is finally out! doi.org/10.1038/s414...
We show how loop-extruding SMC complexes can maintain DNA entrapment while bypassing obstacles on DNA — including transcription machinery & potentially other SMCs.
A lucky convergence of 3 projects lead to the initial discovery!
We show how loop-extruding SMC complexes can maintain DNA entrapment while bypassing obstacles on DNA — including transcription machinery & potentially other SMCs.
A lucky convergence of 3 projects lead to the initial discovery!
Reposted by Stephan Gruber
Glad to see this out after a rather interesting review/publication process!
www.nature.com/articles/s41...
www.nature.com/articles/s41...
The SMC Hinge is a Selective Gate for Obstacle Bypass - Nature Communications
SMC complexes are ring-shaped motors that fold DNA by extruding loops, but how they navigate large DNA obstacles is unclear. Here, Liu et al., show that SMC complexes bypass obstacles by threading obs...
www.nature.com
November 25, 2025 at 2:39 PM
Glad to see this out after a rather interesting review/publication process!
www.nature.com/articles/s41...
www.nature.com/articles/s41...
Reposted by Stephan Gruber
Prashant Singh in the lab of Tina Iverson at Vanderbilt published this image of the bacterial 🦠flagellar motor, a detailed molecular model made possibly by CryoEM 🔬.
The similarity to mechanical motors are strong enough we can use terms like stator, rotor, rod & gearing to describe it.
The similarity to mechanical motors are strong enough we can use terms like stator, rotor, rod & gearing to describe it.
November 17, 2025 at 10:31 PM
Prashant Singh in the lab of Tina Iverson at Vanderbilt published this image of the bacterial 🦠flagellar motor, a detailed molecular model made possibly by CryoEM 🔬.
The similarity to mechanical motors are strong enough we can use terms like stator, rotor, rod & gearing to describe it.
The similarity to mechanical motors are strong enough we can use terms like stator, rotor, rod & gearing to describe it.
Reposted by Stephan Gruber
🌍Open call: Junior Group Leader positions!
Join a world-class biomedical research institute at the heart of the Vienna BioCenter, where curiosity drives discovery.
Lead your own lab, pursue bold ideas, and shape the future of science at the IMP: www.imp.ac.at/career/open-...
Join a world-class biomedical research institute at the heart of the Vienna BioCenter, where curiosity drives discovery.
Lead your own lab, pursue bold ideas, and shape the future of science at the IMP: www.imp.ac.at/career/open-...
November 10, 2025 at 1:26 PM
🌍Open call: Junior Group Leader positions!
Join a world-class biomedical research institute at the heart of the Vienna BioCenter, where curiosity drives discovery.
Lead your own lab, pursue bold ideas, and shape the future of science at the IMP: www.imp.ac.at/career/open-...
Join a world-class biomedical research institute at the heart of the Vienna BioCenter, where curiosity drives discovery.
Lead your own lab, pursue bold ideas, and shape the future of science at the IMP: www.imp.ac.at/career/open-...
Reposted by Stephan Gruber
What Rosalind Franklin truly contributed to the discovery of DNA’s structure. A really informative article, perfect for a weekend coffee read. www.nature.com/articles/d41...
What Rosalind Franklin truly contributed to the discovery of DNA’s structure
Franklin was no victim in how the DNA double helix was solved. An overlooked letter and an unpublished news article, both written in 1953, reveal that she was an equal player.
www.nature.com
November 8, 2025 at 9:21 AM
What Rosalind Franklin truly contributed to the discovery of DNA’s structure. A really informative article, perfect for a weekend coffee read. www.nature.com/articles/d41...
This paper was retracted (by the authors) a long time ago:
pubmed.ncbi.nlm.nih.gov/15178751/
However, I cannot find a retraction notice on the DOI page:
www.science.org/doi/10.1126/...
Is this standard practice, or an oversight?
@science.org
pubmed.ncbi.nlm.nih.gov/15178751/
However, I cannot find a retraction notice on the DOI page:
www.science.org/doi/10.1126/...
Is this standard practice, or an oversight?
@science.org
The bacterial condensin MukBEF compacts DNA into a repetitive, stable structure - PubMed
Condensins are conserved proteins containing SMC (structural maintenance of chromosomes) moieties that organize and compact chromosomes in an unknown mechanism essential for faithful chromosome partitioning. We show that MukBEF, the condensin in Escherichia coli, cooperatively compacts a single DNA …
pubmed.ncbi.nlm.nih.gov
November 7, 2025 at 9:04 AM
This paper was retracted (by the authors) a long time ago:
pubmed.ncbi.nlm.nih.gov/15178751/
However, I cannot find a retraction notice on the DOI page:
www.science.org/doi/10.1126/...
Is this standard practice, or an oversight?
@science.org
pubmed.ncbi.nlm.nih.gov/15178751/
However, I cannot find a retraction notice on the DOI page:
www.science.org/doi/10.1126/...
Is this standard practice, or an oversight?
@science.org
Very nice Preview by @bramkamplab.bsky.social on the SMC DNA loading paper by our @roisnehamelinf.bsky.social
"Weaving the loops of life: DNA loading by loop-extrusion machines in plasmid defense and genome organization"
Molecular Cell www.cell.com/molecular-ce...
"Weaving the loops of life: DNA loading by loop-extrusion machines in plasmid defense and genome organization"
Molecular Cell www.cell.com/molecular-ce...
November 6, 2025 at 6:41 PM
Very nice Preview by @bramkamplab.bsky.social on the SMC DNA loading paper by our @roisnehamelinf.bsky.social
"Weaving the loops of life: DNA loading by loop-extrusion machines in plasmid defense and genome organization"
Molecular Cell www.cell.com/molecular-ce...
"Weaving the loops of life: DNA loading by loop-extrusion machines in plasmid defense and genome organization"
Molecular Cell www.cell.com/molecular-ce...
Reposted by Stephan Gruber
#microsky #phagesky
Mycobacterium #phage review by Graham Hatfull covering the state of the art
www.pnas.org/doi/10.1073/...
Mycobacterium #phage review by Graham Hatfull covering the state of the art
www.pnas.org/doi/10.1073/...
All the world’s a phage | PNAS
A renewed interest in bacteriophages has emerged from the explosive discovery of the
complex pan-immune bacterial defense system and a revival of t...
www.pnas.org
October 31, 2025 at 10:00 AM
#microsky #phagesky
Mycobacterium #phage review by Graham Hatfull covering the state of the art
www.pnas.org/doi/10.1073/...
Mycobacterium #phage review by Graham Hatfull covering the state of the art
www.pnas.org/doi/10.1073/...
Reposted by Stephan Gruber
📢 Open Call! The Max Perutz Labs invite applications for a Full Professorship in Integrative Structure Biology with a focus on in situ structural biology using cryo-electron tomography (cryo-ET) and related methods. More details ➡️ tinyurl.com/brswbymu
October 31, 2025 at 9:24 AM
📢 Open Call! The Max Perutz Labs invite applications for a Full Professorship in Integrative Structure Biology with a focus on in situ structural biology using cryo-electron tomography (cryo-ET) and related methods. More details ➡️ tinyurl.com/brswbymu
Reposted by Stephan Gruber
Really cool!
But Bluesky has flipped your picture over - it now shows positively supercoiled left-handed DNA :-(.
But Bluesky has flipped your picture over - it now shows positively supercoiled left-handed DNA :-(.
Lab’s first paper is out!! We show the first structures of #Asgard #chromatin by #cryo-EM 🧬❄️
Asgard histones form closed and open hypernucleosomes. Closed are conserved across #Archaea, while open resemble eukaryotic H3–H4 octasomes and are Asgard-specific. More here: www.cell.com/molecular-ce...
Asgard histones form closed and open hypernucleosomes. Closed are conserved across #Archaea, while open resemble eukaryotic H3–H4 octasomes and are Asgard-specific. More here: www.cell.com/molecular-ce...
October 29, 2025 at 9:15 PM
Really cool!
But Bluesky has flipped your picture over - it now shows positively supercoiled left-handed DNA :-(.
But Bluesky has flipped your picture over - it now shows positively supercoiled left-handed DNA :-(.
Reposted by Stephan Gruber
October 24, 2025 at 4:06 AM
Reposted by Stephan Gruber
who would have thought! phage N15 TelN telomerase has more than one job!
(and no, it's not 'moonlighting')
great work from the gruber lab 👏
#MicroSky + #PhageSky
(and no, it's not 'moonlighting')
great work from the gruber lab 👏
#MicroSky + #PhageSky
E. coli bacteriophage N15 suppresses Mre11-Rad50-mediated end degradation of its linear genome via a telomere-resolution-independent function of its telomere resolvase TelN
#RefereedPreprint c/o @reviewcommons.org by @gruberlab.bsky.social
www.embopress.org/doi/full/10....
#RefereedPreprint c/o @reviewcommons.org by @gruberlab.bsky.social
www.embopress.org/doi/full/10....
October 20, 2025 at 8:59 PM
Reposted by Stephan Gruber
E. coli bacteriophage N15 suppresses Mre11-Rad50-mediated end degradation of its linear genome via a telomere-resolution-independent function of its telomere resolvase TelN
#RefereedPreprint c/o @reviewcommons.org by @gruberlab.bsky.social
www.embopress.org/doi/full/10....
#RefereedPreprint c/o @reviewcommons.org by @gruberlab.bsky.social
www.embopress.org/doi/full/10....
October 20, 2025 at 1:19 PM
E. coli bacteriophage N15 suppresses Mre11-Rad50-mediated end degradation of its linear genome via a telomere-resolution-independent function of its telomere resolvase TelN
#RefereedPreprint c/o @reviewcommons.org by @gruberlab.bsky.social
www.embopress.org/doi/full/10....
#RefereedPreprint c/o @reviewcommons.org by @gruberlab.bsky.social
www.embopress.org/doi/full/10....
This was a fun collaboration between Ophélie & the @seegerlab.bsky.social using sybody libraries to target the SMC complex in living bacteria. With a suprising finding: the 14 isolated sybodies bind to the middle of the SMC coiled coil rather than the more conserved ATPase heads.
Single Domain Antibody Inhibitors Target the Coiled Coil Arms of the Bacillus subtilis SMC complex https://www.biorxiv.org/content/10.1101/2025.10.16.682983v1
October 20, 2025 at 8:15 AM
This was a fun collaboration between Ophélie & the @seegerlab.bsky.social using sybody libraries to target the SMC complex in living bacteria. With a suprising finding: the 14 isolated sybodies bind to the middle of the SMC coiled coil rather than the more conserved ATPase heads.
Reposted by Stephan Gruber
Single Domain Antibody Inhibitors Target the Coiled Coil Arms of the Bacillus subtilis SMC complex https://www.biorxiv.org/content/10.1101/2025.10.16.682983v1
October 17, 2025 at 11:18 PM
Single Domain Antibody Inhibitors Target the Coiled Coil Arms of the Bacillus subtilis SMC complex https://www.biorxiv.org/content/10.1101/2025.10.16.682983v1
Reposted by Stephan Gruber
Online Now: Mechanism of DNA entrapment by a loop-extruding Wadjet SMC motor Online now:
Mechanism of DNA entrapment by a loop-extruding Wadjet SMC motor
Wadjet is an SMC-based prokaryotic defense system that eliminates plasmid DNA. Roisné-Hamelin et al. present structures capturing key steps of its DNA-loading mechanism. This work reveals how Wadjet topologically entraps DNA by SMC dimer rotation around DNA and defines the starting point of loop extrusion by the SMC motor.
dlvr.it
October 9, 2025 at 3:20 PM
Online Now: Mechanism of DNA entrapment by a loop-extruding Wadjet SMC motor Online now:
Reposted by Stephan Gruber
New online: Structure and activation mechanism of a Lamassu phage and plasmid defense system
Structure and activation mechanism of a Lamassu phage and plasmid defense system
Nature Structural & Molecular Biology, Published online: 14 October 2025; doi:10.1038/s41594-025-01677-4Li et al. show that a Lamassu defense system protects bacteria from phage infection by activating a lethal tetrameric DNA-cutting enzyme. In the absence of phages, a protein clamp holds the enzyme as an inactive monomer, preventing self-damage.
go.nature.com
October 14, 2025 at 11:15 AM
New online: Structure and activation mechanism of a Lamassu phage and plasmid defense system