Out now! In collaboration with Hiroshi Nishimasu's lab, we uncover how a dual reverse transcriptase immune system builds double-stranded DNA from both RNA and protein templates. www.cell.com/cell/abstrac... Previous thread for the preprint: bsky.app/profile/ster...

Coordinated RNA- and protein-templated synthesis of double-stranded DNA by a dual reverse transcriptase immune system

Bacterial reverse transcriptases defend against viruses, yet how their DNA products stop infection remains unknown. Bacteriophage inhibition of a host recombination enzyme activates the DRT3 defense s...

cell.com

We’re so excited to share our new paper, where we tackle the wealth of structural and functional diversity of anti-phage sensors across bacteria (1/6)

Nature@nature.com · last wk.

Nature research paper: Diverse bacterial pattern recognition receptors sense the core phage proteome go.nature.com/45fpXCZ

In situ #CryoEM structures of rice photosystem supercomplexes #photosynthesis #plants #StructuralBiology @nature.com www.nature.com/articles/s41...

In situ structures of plant photosystem supercomplexes - Nature

The cryo‑EM structure of the Oryza sativa photosystem II–light harvesting complex II supercomplex in its native membrane reveals the intact plant photosystem architecture, retaining physiologically re...

nature.com

Happy to share our latest paper! www.science.org/doi/10.1126/... We visualized by cryo-EM how a disease-causing anti-HPA-1a antibody binds to integrin αIIbβ3 and locks it in an inactive state Great colab with Coert Margadant’s lab & groups at Osaka Univ, Sanquin, CNB-CSIC, ISBG Details below… 1/9

📢Grateful to institutions that made this work possible: ➡️Landsteiner Foundation for Blood Transfusion Research ➡️MICIUN AEI and ERDF @ageinves.bsky.social ➡️Instruct-ERIC @instruct-eric.bsky.social for access to cryo-EM & imaging analysis @cryoemcnbcsic.bsky.social @instructi2pc.bsky.social (9/9)

In this manner, the Fab not only creates steric hindrance during extension, but it likely prevents the initial movements, acting as a lock!. Hence, we named it the “His-Tyr lock” 🔒 (7/9)

One key contact occurs between H117-Y118 of the antibody heavy chain contact the disulfide bridge C473-C503 of the I-EGF2. This disulfide is the pivoting point between the I-EGF1 and I-EGF2 during αIIbβ3 extension and activation… (6/9)

Fab 26.4 contacts not only the PSI domain, but also the I-EGF1 and I-EGF2 domains. The interactions with the I-EGF1/2 domains are key to understand how Ab 26.4 prevents integrin activation … (4/9)

To answer this question, we solved the cryo-EM structure of the Fab fragment of 26.4 bound to αIIbβ3. We found integrin aIIbb3 in the complex is in a bent-closed (i.e. inactive) state. How does the antibody stabilized this inactive conformation? … (3/9)

Maternal anti-HPA1a antibodies recognize Leu33 in the PSI domain of β3, causing fetal/neonatal alloimmune thrombocytopenia (FNAIT) One such antibody, named 26.4, blocks αIIbβ3 from binding fibrinogen after thrombin stimulation; a key step in clot formation. How does 26.4 bind the integrin?… (2/9)

Happy that our most recent paper on nucleotide excision repair mechanisms has now been published in Science Advances. This project was led by @natalia-mg.bsky.social and @callumhaste.bsky.social and focused on visualising early steps of the NER process by #cryoEM. www.science.org/doi/10.1126/...

Visualization of stepwise derepression of TFIIH in global genome nucleotide excision repair

Cryogenic electron microscopy captures nucleotide excision repair complexes assembling on damaged DNA templates.

science.org

High-resolution cryo-EM structure of integrin αIIbβ3 bound to disease-causing maternal HPA-1a antibody that blocks integrin activation pubmed.ncbi.nlm.nih.gov/42467762/ #cryoEM

Happy to share our latest pre-print on the Druantia defense system. We find that Type III Druantia uses a cooperative helicase-nuclease mechanism to sense and degrade replication-associated forked DNA structures. www.biorxiv.org/content/10.6... A🧵

PhD opening in my lab @jagiellonskiuni.bsky.social: using AI to predict how phage enzymes break down bacterial capsules — joint work with ML group GMUM and Zuzanna Drulis-Kawa's phage lab (Wrocław), spanning genomics, AI & evolution. mostowylab.com/job-phd-ai-d... Deadline: 15 August 2026

Another amazing beast in the zoo of bacterial anti-phage defences

Arturo Carabias@arturocdr.bsky.social · 3w ago

🧬 Thrilled to share our latest @biorxiv-microbiol.bsky.social preprint! Here we find that Retron-IX build crazy supramolecular rings scaffolded by DNA molecules that sense phage infection! www.biorxiv.org/content/10.6... Read more below🧵! (1/X)

Tremendous bluesky tutorial by @arturocdr.bsky.social explaining our recent paper in colab with @rafomics.bsky.social enjoy it!!!

Arturo Carabias@arturocdr.bsky.social · 3w ago

🧬 Thrilled to share our latest @biorxiv-microbiol.bsky.social preprint! Here we find that Retron-IX build crazy supramolecular rings scaffolded by DNA molecules that sense phage infection! www.biorxiv.org/content/10.6... Read more below🧵! (1/X)

++ For a deeper dive into the mechanism, @arturocdr.bsky.social has a fantastic thread, including a beautiful animation of the Retron IX ring! 👇💍🔥 bsky.app/profile/artu...

Arturo Carabias@arturocdr.bsky.social · 3w ago

🧬 Thrilled to share our latest @biorxiv-microbiol.bsky.social preprint! Here we find that Retron-IX build crazy supramolecular rings scaffolded by DNA molecules that sense phage infection! www.biorxiv.org/content/10.6... Read more below🧵! (1/X)

10/10 Finally, HUGE congrats to co-firsts @arturocdr.bsky.social & Ruiliang Zhao 💪 & to all the other amazing co-authors who made this happen! May the (Retron IX) force be with you ⚔️ www.biorxiv.org/content/10.6...

A DNA-scaffolded Retron Ring Mediates Antiphage Immunity

Retrons are a diverse family of bacterial defence systems that couple reverse transcriptase (RT) activity to antiphage immunity by producing multicopy single-stranded DNA (msDNA). Yet, the molecular m...

biorxiv.org

19/10 Exciting to see these beautiful complementary studies alongside ours. Check them out! 🔥� 1️⃣ Grace Hibshman (@nogaleslab.bsky.social) + @seth-shipman.bsky.social labs: biorxiv.org/content/10.6... 2️⃣ @kotarokiga.bsky.social & H. Nishimashu labs: biorxiv.org/content/10.6...

Higher-order assembly of a type IX retron enables exploitation for designer antimicrobials

Bacterial defense systems provide a rich reservoir for biotechnological innovation. Retrons are tripartite abortive infection systems that detect phage invasion using reverse-transcribed DNA (msDNA), ...

biorxiv.org

8/10 Why sense B14T? 🤔 Speculation: rec-like nucleases may help phages repair/recombine to escape DNA-targeting immunity. Retron IX could act as a safeguard, detecting phages equipped to evade these defenses. Note it often co-occurs with DNA-targeting systems...

7/10 Our model 🧬👇 🔴OFF: RT-synthesized DNA scaffolds the ring and restrains the toxic RNase. 🟢ON: phage nucleases cut msDNA → ring collapses → RNase fires → host tRNAs shredded → infection blocked! 🛡️

6/10 Unleashed, the HEPN RNase cleaves host tRNAs indiscriminately at the anticodon loop ✂️ Protein synthesis stops & phage replication is halted, a strategy shared by many antiviral systems💥

5/10 Escaper analysis revealed the trigger: a phage-encoded nuclease (B14T) B14T snips the msDNA ✂️, the ring collapses 💥, and the RNase is released ⛓️‍💥. But what does it target?

4/10 In fact, early on we joked that the repeating subunits looked like Star Wars TIE fighters 🚀 Note the HEPN catalytic pocket sits exactly where the laser cannons fire... "Convergent evolution"!? 😏⚔️

3/10 CryoEM revealed an unexpected supramolecular ring, with HEPN dimers lining its inner rim, held inactive by the DNA-scaffold🔒 I imagine a fleet of "flying saucers" patrolling the cytoplasm, cannons armed & ready to fire... 🛸👽

2/10 We teamed up with @arturocdr.bsky.social (@guillermo-montoya.bsky.social's lab) to study Retron IX! The system = an RT, ncRNA, HTH–KH protein, and a toxic HEPN RNase, and provides potent defence against diverse phages ⚔️

1/10 🚨Preprint! One RING to rule them all (phages)👑💍⚔️ Bacteria build giant DNA-scaffolded RNase rings (larger than the ribosome!) to shut down viral infection🧬🧵👇 biorxiv.org/content/10.6...

🧬 Thrilled to share our latest @biorxiv-microbiol.bsky.social preprint! Here we find that Retron-IX build crazy supramolecular rings scaffolded by DNA molecules that sense phage infection! www.biorxiv.org/content/10.6... Read more below🧵! (1/X)

One of the coolest structures presented at the recent SISB2026 meeting, great to see this story from @rafomics.bsky.social and @guillermo-montoya.bsky.social on a giant retron ring-shaped assembly now out: www.biorxiv.org/content/10.6...

🚨 We're hiring! My new lab at EMBL Hamburg is looking for a Research Technician. I'm looking for someone excited by phages, metabolism, enzymes, structural biology and bacterial immunity—if you know the right person, please share this post!🧵⬇️ Apply here: embl.wd103.myworkdayjobs.com/en-US/EMBL/j...

Research Technician (Osterman Group – Metabolism-driven immunity)

EMBL Hamburg / CSSB The European Molecular Biology Laboratory (EMBL) is Europe’s flagship life sciences organization, with more than 110 independent research groups across Heidelberg, Hamburg, Grenobl...

embl.wd103.myworkdayjobs.com