Anjana Badrinarayanan

Repeated duplications and losses shaped SMC complex evolution from archaeal ancestors to modern eukaryotes Van Hooff et al. reconstruct the evolutionary histories of eukaryotic SMC complexes, molecular machineries that organize chromosomes. SMC complexes were fully present in the last eukaryotic common ancestor (LECA) but have been frequently lost during evolution. Remarkably, these complexes originated from an ancient duplication in archaeal ancestors, suggesting that sophisticated chromosome organization predated eukaryotes.

Repeated duplications and losses shaped SMC complex evolution from archaeal ancestors to modern eukaryotes: Cell Reports https://www.cell.com/cell-reports/fulltext/S2211-1247(25)00626-6?rss=yes

Thanks Erin!

Live tracking of replisomes reveals nutrient-dependent regulation of replication elongation rates in Caulobacter crescentus Adhikashreni et al. use quantitative live-cell imaging to track cell-cycle dynamics in hundreds of individual bacteria. They observe nutrient-dependent regulation of replication elongation rates that ...

Happy to share Asha Joseph and Inchara Adhikashreni's latest work from the lab, describing replisome speed variation in Caulobacter!

www.cell.com/current-biol...

Schematic showing how Hankyphage has multiple mechanisms of generating randomness in its own and its bacterial host genomes. (1) RepCHP-dependent spontaneous induction of prophage, (2) incomplete packaging leading to defective virions and free tails in combination with low-level complete packaging and potential transduction events, (3) intrachromosomal transposition leading to genetic variation in the host genome, and (4) diversity generating retroelements within the phage genome impacting the host range of the phage. Created with BioRender.

The biology and ecological impact of #phages in the mammalian gut are poorly understood. This Primer explores a @plosbiology.org study that provides a glimpse into the disruptive biology of the #Hankyphages, parasites of the ubiquitous Bacteroidaceae. 🧪 Primer: plos.io/3RukgtJ Paper: plos.io/41Rr22S

Alt : Structure of the apo Lamassu protein complex. Schematic model of the active LmuA tetramer nuclease (top right). Lamassu icon (top left).

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.

Side view of the structure of a monomer of type II Wadjet.

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.

Future Directions of the Prokaryotic Chromosome Field In September 2023, the Biology and Physics of Prokaryotic Chromosomes meeting ran at the Lorentz Center in Leiden, The Netherlands. As part of the workshop, those in attendance developed a series of ....

In @molecularmicro.bsky.social: two special issues on Prokaryotic Chromosome Organization. Many excellent contributions, including a vision article: 'Future directions of the Prokaryotic Chromosome Field', outcome of BioPhyChrom 2023 @biophychrom.bsky.social onlinelibrary.wiley.com/doi/10.1111/...

Cellular responses to RNA damage RNA plays a central role in protein biosynthesis and performs diverse regulatory and catalytic functions, making it essential for all processes of life. Like DNA, RNA is constantly subjected to damage...

Cellular responses to RNA damage: Cell
Such a great and timely review for a topic that remained under-explored for such a long time but has attracted a lot of attention in the last few years. The field is now moving in leaps and bounds. #RNAsky

www.cell.com/cell/fulltex...

KorB switching from DNA-sliding clamp to repressor mediates long-range gene silencing in a multi-drug resistance plasmid - Nature Microbiology Structural and single-molecule analyses show the CTPase, KorB, is a sliding DNA clamp that interacts with a clamp-locking protein KorA to inhibit gene expression over distances of more than 1 kb in th...

OUT NOW: KorB is a DNA clamp which slides along DNA to mediate long-range gene silencing upon interaction with the clamp-locking KorA protein

by Tung Le & co @johninnescentre.bsky.social

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

Single-stranded DNA binding to the transcription factor PafBC triggers the mycobacterial DNA damage response The structure of PafBC in its active conformation reveals the binding mode of the activating ligand at the PafBC WYL domains.

Important paper from the Weber-Ban lab about the mechanism of activation of PafBC in the mycobacterial DNA damage response.

Single-stranded DNA binding to the transcription factor PafBC triggers the mycobacterial DNA damage response | Science Advances www.science.org/doi/10.1126/...

Sequence-dependent activity and compartmentalization of foreign DNA in a eukaryotic nucleus In eukaryotes, DNA-associated protein complexes coevolve with genomic sequences to orchestrate chromatin folding. We investigate the relationship between DNA sequence and the spontaneous loading and a...

What happens to bacterial genomes when they're cloned into yeast? Do they transcribe, do they get silenced, do they get packaged away from the rest of the DNA? This cool study congrats to the Koszul lab team at Pasteur for this great work.
www.science.org/doi/10.1126/...

When does a DNA polymerase degrade DNA? Read Akshaya’s work from the lab to find out more!

Fun work on the regulation of the bacterial SOS response to DNA damage. Led by the fantastic @adityakamat.bsky.social!

#MicroSky
CTPases, the new kids on the block

New discovery from our #CDlab reported in Cell @cp-cell.bsky.social today:
SMC motor proteins have a left-right ‘gearbox’ and can switch direction in DNA loop extrusion!

www.sciencedirect.com/science/arti...

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So happy to see @stcmicrobeblog.bsky.social active here!

Is there a future for STC? by Roberto – The short answer to that question is an enthusiastic YES! Of course, there is a future for STC, and I think it is bright. The long answer, well... that's what this post is all about It r...

STC is back

schaechter.asmblog.org/schaechter/2...
#MicroSky

This was an amazing collaboration, we had the luxury of years of great conversations with @wallaceucsf.bsky.social and his team, as well as our other @HFSP partners @anjbadri.bsky.social and Johan Paulsson. Thanks for telling the story here, Wallace!