Luis E. Valentin-Alvarado

Most plasmids described in E. coli are small compared to the megaplasmids we identified here! Check out the preprint if you want to learn about these mysterious large elements and their potential functions 🧬. I’m very grateful to have had the opportunity to work on this in @banfieldlab.bsky.social

A miniature CRISPR–Cas10 enzyme confers immunity by inhibitory signalling - Nature Panoptes, an anti-phage defence system against virus-mediated immune suppression, is revealed.

Now online at @nature.com we show how the Panoptes defense system protects against viruses that attempt immune evasion - and expands our understanding of the role of oligonucleotides in immunity.

Check out this work co-led with @benadler.bsky.social here:

www.nature.com/articles/s41...

New paper online at @nature.com from co-leads @erinedoherty.bsky.social + @benadler.bsky.social !

The Panoptes system uses decoy cyclic nucleotides to defend against phage - Nature The Panoptes antiphage system defends bacteria by detecting phage-encoded counter-defences that sequester cyclic nucleotide signals, triggering membrane disruption and highlighting a broader strategy of sensing immune evasion through second-messenger surveillance.

Our story describing the Panoptes bacterial immune defense system is now finally peer-reviewed and published today! www.nature.com/articles/s41...

A miniature CRISPR–Cas10 enzyme confers immunity by inhibitory signalling - Nature Panoptes, an anti-phage defence system against virus-mediated immune suppression, is revealed.

Today in @nature.com , we highlight how a cousin of CRISPR-Cas10, mCpol, establishes an evolutionary trap in anti-phage immune systems.

Check out @erinedoherty.bsky.social and my work from @doudna-lab.bsky.social lab here:
www.nature.com/articles/s41...

Microbiology and Immunology – Faculty Position (Ladder Rank) – Assistant Professor University of California, San Francisco is hiring. Apply now!

Our Department of Microbiology & Immunology at UCSF is running a faculty search this year for a new Assistant Professor! Please see the ad below for details. Searching for a great colleague, mentor, and scientist!
aprecruit.ucsf.edu/JPF05807

Join us tomorrow if you can. Link below to register.

New blog post!

metaMDBG (@gaetanbenoit.bsky.social) and Myloasm (@jimshaw.bsky.social) have had recent releases, so I updated the benchmarks from the Autocycler paper:
rrwick.github.io/2025/09/23/a...

Both tools improved considerably! Time to update your conda environments 😄

Assistant Professor Plant-Microbe Interactions We seek a creative, collaborative, and visionary plant biologist to establish an internationally recognized research program at the forefront of plant-microbe interactions aimed at understanding how t...

The Department of Biology at Colorado State University is hiring an Assistant Professor in the area of plant-microbe interactions! Please spread the word!

jobs.colostate.edu/postings/165...

❤️❤️❤️ CSU. Fort Collins is a lovely place to live, and students / faculty are awesome. I should know, I taught there for 15 years! Apply!

This is the dept where I got my PhD! Hiring for microbiology!

How can we understand the earliest events in evolution of eukaryotic immunity? @yao-li.bsky.social reports incredible molecular fossils of complete bacterial-like operons in eukaryotes that illuminate how animal immunity was first acquired from anti-phage defense

www.biorxiv.org/content/10.1...

🦠Exciting PhD opportunity @ ETH Zürich!
Our Environmental Microbiology group is looking for a motivated student to study microbial processes in peatland restoration — from fieldwork to metagenomics and lab experiments.

🗓 Start: Spring 2026
⏳ Deadline: 3 Oct 2025
👉 Apply: lnkd.in/eSPiy6vQ
Please 🔁

Genomic and physiological characterization of 'Candidatus Methylocystis sumavensis', a novel acid-tolerant methanotroph from peatland Methanotrophic bacteria in peatlands mitigate emissions of methane (CH4), a potent greenhouse gas. Yet, the identity, physiology, and adaptive traits of methanotrophs inhabiting acidic peatlands are s...

📢 🦠 A new methanotroph from Czech peat! Through an effort led by PhD student in my group Justus Nweze we isolated and describe a new CH4-muncher. Potential for a flexible (annaerobic) metabolisms and cool pH adaptations.

www.biorxiv.org/content/10.1...
#microbesky #microbiomesky

A widespread family of viral sponge proteins reveals specific inhibition of nucleotide signals in anti-phage defense Chang et al. discover anti-CBASS 4 (Acb4), a family of viral sponges that inhibits bacterial immunity by sequestering nucleotide immune signals. Acb4 homologs in phages that infect hosts across all ma...

The beautiful, ever-expanding universe of viral proteins targeting nucleotide immune signals!

Paper by @reneechang.bsky.social in @cp-molcell.bsky.social on a nucleotide sponge www.cell.com/molecular-ce...

and preprint by @doudna-lab.bsky.social on viral nucleases www.biorxiv.org/content/10.1...

New pre-print from Doudna lab members @erinedoherty.bsky.social & @jnoms.bsky.social ✨

Here we explore how recurrent adaptation of a single anti-defense protein fold enables evasion of distinct immune systems.

At the request of @bradleyph.bsky.social, we have now added the Bacterial and Archaeal trees (credit to @aroneys.bsky.social) used to infer the GlobDB taxonomy to the website globdb.org

Feel free to reach out if there's other resources you'd like to see added. No promises, but happy to chat 🖥️🧬🦠

Does sequence clustering confound AlphaFold2? Predicting multiple conformational states of proteins represents a significant open challenge in structural biology. Increasingly many methods have be…

Does sequence clustering confound AlphaFold2?
www.sciencedirect.com/science/arti... From @hkws.bsky.social

Caliditerrarchaeota, a new sister to Nanohaloarchaeota, provides insights into the evolution of DPANN halophily The Nanohaloarchaeota are a clade of halophilic symbionts with small cells and genomes. Originally placed within the Euryarchaeota, they are now widely thought to belong to the DPANN archaea. However,...

New preprint up now!

Interested in the evolution of halophily within DPANN archaea we decided to investigate the sister phylum to the Nanohaloarchaeota, GTDB phylum EX4484-52, for which we propose the name Caliditerrarchaeota
www.biorxiv.org/content/10.1...

Recurrent acquisition of nuclease-protease pairs in antiviral immunity Antiviral immune systems diversify by integrating new genes into existing pathways, creating new mechanisms of viral resistance. We identified genes encoding a predicted nuclease paired with a trypsin...

Excited to finally share this work!
We noticed a pair of genes - a nuclease and a protease - shuffles between antiviral systems. We show how proteolysis activates the nuclease, triggering defense in known and unknown immune contexts.
tinyurl.com/2uwwy4ty

‼️ New pre-print from co-leads @owentuck.bsky.social and Jason Hu! Check out this fascinating example of how coevolution enables defense system innovation.

Very proud to have our lab’s first work published in @cp-cellhostmicrobe.bsky.social!

In this work, we use functional metagenomics to find phage defenses from human and soil microbiomes!

Congrats to first author @luis840alberto.bsky.social !

www.cell.com/cell-host-mi...

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if i were a better person i would do a tweetorial on our recent paper - but, hey, read the paper. its right there, waiting for you. #Giantvirus #histones are cool! their #nucleosomes are cool. check it out.! thats the tweetorial.
rdcu.be/exXBX

WitChi: Efficient Detection and Pruning of Compositional Bias in Phylogenomic Alignments Using Empirical Chi-Squared Testing Convergent evolution, where unrelated taxa independently evolve similar nucleotide or amino acid compositions, can introduce compositional bias into biological sequence data. Such biases distort phylo...

1.
🧵 New preprint out!
WitChi: a fast, open-source Python tool to detect, quantify & prune compositional bias in MSAs.
Lightweight, tree-free, scalable to 5k+ taxa... so we applied it to the GTDB archaea MSA.
#ArchaeaSky #MEvoSky #MicroSky
🔗 doi.org/10.1101/2025...
💻 github.com/stephkoest/w...

Our latest work, driven by the fabulous @stephkoe.bsky.social! WitChi takes care of compositional bias in large phylogenomic datasets! WitChi is fast, efficient and free, try it out!

With @kassipan.bsky.social and @danieltamarit.bsky.social

#Archaea #GRC folks, be sure to catch work by @oceancait.bsky.social representing our group this week in Switzerland.

She'll talk about new Asgard archaea enrichments form the Oregon coast. Talk on Sunday, Poster during the week.

A cartoon depiction of the Asgard archaeon Skadiarchaeum sp., named after the Norse goddess of skiing and hunting, Skadi.

In a couple of days, my grad student Stavros Trimmer will present his new Asgard archaea culture at the GRC Archaea. He named it Skadiarchaeum after Skadi, the Norse goddess of skiing and hunting. Cartoon of Skadi based on cryoET, which was performed together with with @florianwollweber.bsky.social

Disorder meets its match Designed protein pockets recognize intrinsically disordered protein regions

Designed protein pockets recognize intrinsically disordered protein regions @science.org
www.science.org/doi/10.1126/...
www.science.org/doi/10.1126/...
www.statnews.com/2025/07/17/n...

This #WorldZoonosesDay, learn five key facts about #zoonotic diseases and how we can prevent future outbreaks.
Check out our infographic: onehealthtrust.org/publications...

🚨 Fresh from the press! We created and analyzed over 100 in vitro cyanobacterial consortia using well-characterized model cyanobacterial hosts to better understand how cyanobacteria recruit and interact with their microbiomes.

Check it out: doi.org/10.1093/isme...