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Stephan Gruber

@gruberlab.bsky.social

1.2K followers 350 following 60 posts

Microbiologist | Biochemist | Structural Biologist, Lausanne 🇨🇭 | Studying molecular machines (SMC, ParB, Wadjet, Lamassu & more) in chromosome folding, genome maintenance, and DNA defense. 🔬 Lab homepage: wp.unil.ch/gruberlab

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Stephan Gruber @gruberlab.bsky.social · 22h

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...

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Stephan Gruber @gruberlab.bsky.social · 28m

Thank you, Biswajit!

Reposted by Stephan Gruber

DNA Topology Lab @dnatopologylab.bsky.social · 5h

As always, bacteria light the path of discovery.

Stephan Gruber @gruberlab.bsky.social · 22h

For the specialists: the motor units adopt a DNA-holding conformation, a proposed key state of the segment capture model

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Stephan Gruber @gruberlab.bsky.social · 6h

Thanks!

We use the symbol for Wadjet, one of the goddesses personifying the Eye of Ra. Not sure this is entirely correct. I hope she does not mind 😄

Stephan Gruber @gruberlab.bsky.social · 17h

Thank you, Luuk!

Stephan Gruber @gruberlab.bsky.social · 22h

Many thanks to the editor and reviewers for such a constructive, enjoyable process.

Stephan Gruber @gruberlab.bsky.social · 22h

For the specialists: the motor units adopt a DNA-holding conformation, a proposed key state of the segment capture model

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Stephan Gruber @gruberlab.bsky.social · 22h

Other important findings:

Loop extrusion starts with de novo loop formation rather than loop capture.

The two motor units are loaded side-by-side in a tail-to-tail orientation, ready for bidirectional DNA extrusion.

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Stephan Gruber @gruberlab.bsky.social · 22h

and finally, a DNA-loaded state

www.rcsb.org/structure/9QXX

RCSB PDB - 9QXX: JetABC DNA loaded state dimer

JetABC DNA loaded state dimer

www.rcsb.org

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Stephan Gruber @gruberlab.bsky.social · 22h

A half-loaded state:

www.rcsb.org/structure/9QXT

RCSB PDB - 9QXT: E. coli JetABC dimer in the DNA boarding-holding state

E. coli JetABC dimer in the DNA boarding-holding state

www.rcsb.org

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Stephan Gruber @gruberlab.bsky.social · 22h

See the beautiful structures:
A new DNA-boarding state.
www.rcsb.org/structure/9QXS
www.rcsb.org/structure/9QXR

RCSB PDB - 9QXS: E. coli JetABC dimer in a DNA boarding state

E. coli JetABC dimer in a DNA boarding state

www.rcsb.org

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Stephan Gruber @gruberlab.bsky.social · 22h

Florian determined structures of several DNA-loading intermediates using clever protein engineering & cryo-EM with help from Dubochet Center for Imaging @fbm-unil.bsky.social & @igbmc.bsky.social
He found that the large SMC dimers rotate around DNA to close the ring and topologically entrap DNA.

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Stephan Gruber @gruberlab.bsky.social · 22h

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Reposted by Stephan Gruber

Julia Frunzke @frunzkelab.bsky.social · 2d

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

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

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Reposted by Stephan Gruber

Luca Giorgetti lab @FMI @lucagiorgetti.bsky.social · 15d

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🧵👇

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Reposted by Stephan Gruber

fbm-unil.bsky.social @fbm-unil.bsky.social · 22d

Apply now for FBM #PhD #Fellowships in #Life #Sciences – join one of the Faculty’s leading laboratories.

🚨 Application deadline for fellowships: October 6, 2025.
➡️ www.unil.ch/news/en/1756...

@unil.bsky.social @dmf-unil.bsky.social @dee-unil.bsky.social @dib-unil.bsky.social #fbm #unil

PhD Fellowships in Life Sciences: a competition open to future doctoral students.

Apply now for FBM PhD Fellowships in Life Sciences – join one of the Faculty’s leading laboratories.

www.unil.ch

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Reposted by Stephan Gruber

Plasmid Society @plasmidsociety.bsky.social · 25d

Hey hey hey!
Tomorrow, September 16th at 16:00 UTC, don’t miss the next ISPB virtual seminar!
This session will focus on plasmid elimination with great speakers lined up.

#Plasmid #ISPB #MGEs

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Reposted by Stephan Gruber

Max-Planck-Gesellschaft @maxplanck.de · Sep 9

Springboard for an international scientific career! 🧬🧪🔭⚛️🧠🌱 Call for #MaxPlanckResearchGroups launched; applications are possible until October 14, 2025 www.mpg.de/max-planck-r... #ScienceCareer

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Reposted by Stephan Gruber

Marc Bühler @marcbuhler.bsky.social · Sep 8

We are hiring-join us!

FMI science @fmiscience.bsky.social · Sep 8

🚨 We're hiring, please share! The FMI seeks a tenure-track Group Leader (Assistant Prof) in Structural Biology 🔬
Innovative scientists in genome regulation, RNA metabolism, or protein homeostasis—especially using cutting-edge approaches—apply now at www.fmi.ch/education-ca...

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Stephan Gruber @gruberlab.bsky.social · Sep 5

Thanks to all the reviewers and the editor for their constructive comments and support.

Stephan Gruber @gruberlab.bsky.social · Sep 5

Our Wadjet-II paper by @roisnehamelinf.bsky.social is out in polished form: www.cell.com/structure/fu...

With a great preview by @kevincorbett.bsky.social & @amardeeep.bsky.social highlighting the potential of Wadjets:

Wadjet—Keeping a watchful eye on circular DNA.

www.cell.com/structure/fu...

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Reposted by Stephan Gruber

David Bikard @dbikard.bsky.social · Aug 23

Congratulations Rotem Sorek @soreklab.bsky.social on receiving the Gruber prize today in Stockholm

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Reposted by Stephan Gruber

Anne Chevallereau @annechevallereau.bsky.social · Aug 19

#phagesky

I am looking for phages infecting Streptococcus pneumoniae to test a phenotype - does anyone have some and willing to share ?

Repost appreciated :)

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Reposted by Stephan Gruber

bioRxiv Microbiology @biorxiv-microbiol.bsky.social · Jul 29

Recurrent acquisition of nuclease-protease pairs in antiviral immunity https://www.biorxiv.org/content/10.1101/2025.07.28.667249v1

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Reposted by Stephan Gruber

European Research Council (ERC) @erc.europa.eu · Jul 27

🧬 Ever wonder how metres of #DNA 🧬 fit into a single cell?

@gruberlab.bsky.social, working at @unil.bsky.social uncovered how protein machines fold DNA into loops – key for cell division & genome stability.

Learn more 👉 buff.ly/PrfdXnr

#BioTech #Chromosomes #Crystallography #GeneEditing 🧪

Cracking the code of DNA folding machines

New research has helped to explain how DNA is shaped into loops, a process critical for ensuring chromosomes are properly distributed...

europa.eu

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Reposted by Stephan Gruber

Caleb Lareau @caleblareau.bsky.social · Jul 22

Excited to share a new preprint from the lab with @ryandhindsa.bsky.social ! www.biorxiv.org/content/10.1...

Led by @sherrynyeo.bsky.social, @erinmayc.bsky.social, and friends, we continue our journey to find viral DNA in our favorite place-- the overlooked and discarded reads in existing data! 1/

the treasure trove of all sequencing datasets

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