Florian Roisné-Hamelin
@roisnehamelinf.bsky.social
450 followers 120 following 7 posts
Molecular biologist moving to biochemistry Admirer of Cryo-EM Interested in a lot of things including SMC proteins, telomeres and DNA repair machines
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Delighted to announce our latest work on how Wadjet loads onto and establishes topological entrapment of plasmid DNA prior to initiating loop extrusion. At @gruberlab.bsky.social, Dubochet Center for Imaging and BSI @igbmc.bsky.social

www.cell.com/molecular-ce...
Reposted by Florian Roisné-Hamelin
gruberlab.bsky.social
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
gruberlab.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.
Alt : Structure of the apo Lamassu protein complex. Schematic model of the active LmuA tetramer nuclease (top right). Lamassu icon (top left).
Very nice collaboration with the BSI platform at @igbmc.bsky.social. Streptavidin grids were instrumental to solve a rather drastic anisotropy problem!
Many thanks to the reviewers for their thoughtful and constructive comments on our manuscript.
Delighted to announce our latest work on how Wadjet loads onto and establishes topological entrapment of plasmid DNA prior to initiating loop extrusion. At @gruberlab.bsky.social, Dubochet Center for Imaging and BSI @igbmc.bsky.social

www.cell.com/molecular-ce...
Reposted by Florian Roisné-Hamelin
gruberlab.bsky.social
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...
Reposted by Florian Roisné-Hamelin
gruberlab.bsky.social
This reveals parallels with DNA end protection in eukaryotes and highlights the challenges of having linear chromosomes as well as functional repair of DNA double strand break.

www.biorxiv.org/cgi/content/...
www.biorxiv.org
Reposted by Florian Roisné-Hamelin
veeninglab.com
New tenure track assistant professor position in molecular microbiology in our department @dmf-unil.bsky.social @unil.bsky.social! We are casting a wide net for an experimental molecular microbiologist. Apply here: wwwfbm.unil.ch/releve/appli...
DMF: Tenure Track Assistant Professor towards Associate Professor in Molecular Microbiology - Site des postulations FBM
wwwfbm.unil.ch
Happy to share our latest work. Wadjet-I SMC hinges are gates allowing selective bypass of obstacles connected through ssDNA BUT are dispensable for extrusion of naked DNA.

www.biorxiv.org/content/10.1...
Reposted by Florian Roisné-Hamelin
Reposted by Florian Roisné-Hamelin
cootymccootface.bsky.social
Coot 1.1.14 has been released!

Coming to homebrew and flatpak soon!

- Clark & Labute comes to Coot 1, Moorhen & chapi!
(svg, 2D ligand environment view)
- Solid Symmetry (symmetry that you can see!)
- PAE plot for AlphaFold models
#coot
#molmatinf
Screenshot of 2d ligand environment view, 1x8b 4dfr, 2vtq, 2p4y
Reposted by Florian Roisné-Hamelin
gruberlab.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.
Alt : Structure of the apo Lamassu protein complex. Schematic model of the active LmuA tetramer nuclease (top right). Lamassu icon (top left).
Reposted by Florian Roisné-Hamelin
gruberlab.bsky.social
Happy to share the beautiful structure of a Wadjet SMC complex by @roisnehamelinf.bsky.social, with support from the DCI and @drhonsworth.bsky.social ! This is a type II Wadjet with unique characteristics including a tandem KITE subunit, distinct coiled coil architecture and a deviant hinge.
Side view of the structure of a monomer of type II Wadjet.
Reposted by Florian Roisné-Hamelin
Pleased to announce the publication of our latest work on how Wadjet senses DNA circularity prior to cleavage. Collaborative effort with @drhonsworth.bsky.social at @gruberlab.bsky.social & Dubochet Center for Imaging. Deep thanks to our advisors and reviewers.

authors.elsevier.com/c/1iXM53vVUP...
gruberlab.bsky.social
Our new work on the Wadjet (JET) anti-plasmid defence system is out:

authors.elsevier.com/a/1iXM53vVUP...

Showing structures of SMC complexes on extruded DNA (first time?)

and blockage (!) of DNA extrusion by obstacles on DNA

and more...
Reposted by Florian Roisné-Hamelin
gruberlab.bsky.social
First preprint 📢 on bsky: New work on the Wadjet defence system by @roisnehamelinf.bsky.social & @drhonsworth.bsky.social revealing beautiful & exciting structures of JET on plasmid DNA. With loop extrusion, obstacles, DNA bending, kinking, cleavage 🦠🧫 🧪
t.co/RaO7IO3zDk 
With help from @DCI_Lausanne
Structures of JetABCD complex on kinked plasmid DNA.