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
· Oct 9
How do SMC complexes load onto DNA to get ready for loop extrusion?
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
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
Reposted by Stephan Gruber
🚨Our paper is out! 🥳
Hijacking a bacterial ABC transporter for efficient genetic code expansion.
Many congrats to everyone involved - a multi-year effort led by @taruniype.bsky.social @maxfottner.bsky.social
www.nature.com/articles/s41...
it all started years ago with a failed experiment
🧵👇 1/9
Hijacking a bacterial ABC transporter for efficient genetic code expansion.
Many congrats to everyone involved - a multi-year effort led by @taruniype.bsky.social @maxfottner.bsky.social
www.nature.com/articles/s41...
it all started years ago with a failed experiment
🧵👇 1/9
Hijacking a bacterial ABC transporter for genetic code expansion - Nature
Bacterial ATP-binding cassette (ABC) transporters can be utilized and engineered to transport non-canonical amino acids into Escherichia coli for highly efficient synthesis of proteins with novel func...
www.nature.com
October 16, 2025 at 2:06 PM
🚨Our paper is out! 🥳
Hijacking a bacterial ABC transporter for efficient genetic code expansion.
Many congrats to everyone involved - a multi-year effort led by @taruniype.bsky.social @maxfottner.bsky.social
www.nature.com/articles/s41...
it all started years ago with a failed experiment
🧵👇 1/9
Hijacking a bacterial ABC transporter for efficient genetic code expansion.
Many congrats to everyone involved - a multi-year effort led by @taruniype.bsky.social @maxfottner.bsky.social
www.nature.com/articles/s41...
it all started years ago with a failed experiment
🧵👇 1/9
And also the bacterial telomere protection paper by Maya, Nicolas, & Ania is out:
doi.org/10.1038/s443...
Great experience with @reviewcommons.org
& @embojournal.org
Feels just right to have the manuscript reviewed without having to target a specific journal from the start.
doi.org/10.1038/s443...
Great experience with @reviewcommons.org
& @embojournal.org
Feels just right to have the manuscript reviewed without having to target a specific journal from the start.
October 15, 2025 at 12:06 PM
And also the bacterial telomere protection paper by Maya, Nicolas, & Ania is out:
doi.org/10.1038/s443...
Great experience with @reviewcommons.org
& @embojournal.org
Feels just right to have the manuscript reviewed without having to target a specific journal from the start.
doi.org/10.1038/s443...
Great experience with @reviewcommons.org
& @embojournal.org
Feels just right to have the manuscript reviewed without having to target a specific journal from the start.
Happy that the final version of our Lamassu work @yli18smc.bsky.social is now out:
www.nature.com/articles/s41...
Thanks again to our awesome collaborators @mblokesch.bsky.social and David and co and Mark Szczelkun and @steven-shaw.bsky.social and the DCI Lausanne @fbm-unil.bsky.social
www.nature.com/articles/s41...
Thanks again to our awesome collaborators @mblokesch.bsky.social and David and co and Mark Szczelkun and @steven-shaw.bsky.social and the DCI Lausanne @fbm-unil.bsky.social
Glad to share the work of @yli18smc.bsky.social and co on Lamassu, a bacterial defense system related to Rad50/Mre11 (RM). While RM carefully trims DNA ends for repair, Lamassu chops up the host chromosome. Our study reveals how it is regulated to minimize damage, activating only during infection.
October 14, 2025 at 9:28 AM
Happy that the final version of our Lamassu work @yli18smc.bsky.social is now out:
www.nature.com/articles/s41...
Thanks again to our awesome collaborators @mblokesch.bsky.social and David and co and Mark Szczelkun and @steven-shaw.bsky.social and the DCI Lausanne @fbm-unil.bsky.social
www.nature.com/articles/s41...
Thanks again to our awesome collaborators @mblokesch.bsky.social and David and co and Mark Szczelkun and @steven-shaw.bsky.social and the DCI Lausanne @fbm-unil.bsky.social
Reposted by Stephan Gruber
We are pleased to highlight this article published by @gruberlab.bsky.social. At DCI, F. Roisne Hamelin and collaborators used electron microscopy — and in particular our streptavidin affinity grids — to reveal the mechanism by which Wadjet binds to the plasmid to initiate loop extrusion.
How do SMC complexes load onto DNA to get ready for loop extrusion?
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
October 14, 2025 at 5:48 AM
We are pleased to highlight this article published by @gruberlab.bsky.social. At DCI, F. Roisne Hamelin and collaborators used electron microscopy — and in particular our streptavidin affinity grids — to reveal the mechanism by which Wadjet binds to the plasmid to initiate loop extrusion.
Reposted by Stephan Gruber
As always, bacteria light the path of discovery.
For the specialists: the motor units adopt a DNA-holding conformation, a proposed key state of the segment capture model
October 10, 2025 at 8:12 AM
As always, bacteria light the path of discovery.
How do SMC complexes load onto DNA to get ready for loop extrusion?
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
October 9, 2025 at 2:43 PM
How do SMC complexes load onto DNA to get ready for loop extrusion?
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
@roisnehamelinf.bsky.social & co discovered that Wadjet, an SMC complex involved in bacterial DNA immunity, performs some impressive molecular gymnastics 🤸♂️🤸♂️🤸♂️.
Check out the new paper: www.cell.com/molecular-ce...
Reposted by Stephan Gruber
Please RT:
We have an opening for a junior group leader position in „Phage Biology & Biotechnology“.
www.fz-juelich.de/de/karriere/...
Interested candidates are encouraged to contact me via email for further details.
@spp2330.bsky.social; @mibinet.bsky.social
We have an opening for a junior group leader position in „Phage Biology & Biotechnology“.
www.fz-juelich.de/de/karriere/...
Interested candidates are encouraged to contact me via email for further details.
@spp2330.bsky.social; @mibinet.bsky.social
Junior Group Leader - Phage Biology & Biotechnology
As a leading research institution for microbial biotechnology the Institute of Bio- and Geosciences - Biotechnology (IBG-1, https://www.fz-juelich.de/de/ibg/ibg-1 ) at the Forschungszentrum Jülich foc...
www.fz-juelich.de
October 8, 2025 at 6:50 AM
Please RT:
We have an opening for a junior group leader position in „Phage Biology & Biotechnology“.
www.fz-juelich.de/de/karriere/...
Interested candidates are encouraged to contact me via email for further details.
@spp2330.bsky.social; @mibinet.bsky.social
We have an opening for a junior group leader position in „Phage Biology & Biotechnology“.
www.fz-juelich.de/de/karriere/...
Interested candidates are encouraged to contact me via email for further details.
@spp2330.bsky.social; @mibinet.bsky.social
Reposted by Stephan Gruber
Really excited to share our latest work led by @mattiaubertini.bsky.social and @nesslfy.bsky.social: we report that cohesin loop extrusion creates rare but long-lived encounters between genomic sequences which underlie efficient enhancer-promoter communication.
www.biorxiv.org/content/10.1...
A🧵👇
www.biorxiv.org/content/10.1...
A🧵👇
September 24, 2025 at 9:45 PM
Really excited to share our latest work led by @mattiaubertini.bsky.social and @nesslfy.bsky.social: we report that cohesin loop extrusion creates rare but long-lived encounters between genomic sequences which underlie efficient enhancer-promoter communication.
www.biorxiv.org/content/10.1...
A🧵👇
www.biorxiv.org/content/10.1...
A🧵👇