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Tung Le @tunglejic.bsky.social · 1d

A ParA-interacting peptide, enabling B-A interaction!!!

Tung Le @tunglejic.bsky.social · 1d

ParB NTPase fold might:
*suggest hidden layer of biological regulation
*maybe a fold as fundamental as P-loop ATPases or Rossmann folds (well, this has to be seen!)
*be a treasure trove of uncharacterized proteins waiting to be studied.

We probably have only scratched the surface.

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Tung Le @tunglejic.bsky.social · 1d

Overall:
ParB-CTPase is like the Swiss Army knife.

*Sometimes it helps form a DNA clamp.
*Sometimes as an enzyme module.
*Sometimes may be as a scaffold.

Evolution keeps re-purposing it for new cellular roles.

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Tung Le @tunglejic.bsky.social · 1d

Some examples from literature already hinted at its versatility:

*In Bacillus, Noc uses CTP to coordinate DNA segregation with cell division.
*In Shigella/E.coli/Pseudomonas, VirB/KorB/BisD regulates gene expression with a CTP switch.
*In archaea/eukaryotes, some are kinases or sulfiredoxins.

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Tung Le @tunglejic.bsky.social · 1d

What is special about ParB-CTPase fold?

*Likely an ancient NTP-binding module
*Also found in plasmids, phages, & chromosomes
*Fused to lineage-specific domains
*Not limited to CTP - can also bind ATP and even GTP!!! (we purified 28 diverse proteins to test NTP preference).

A very versatile fold!

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Tung Le @tunglejic.bsky.social · 1d

But… how widespread is the CTPase fold?
We surveyed 80,000+ proteins across bacteria, archaea, phages, and eukaryotes.

Result: the ParB-CTPase fold is EVERYWHERE.
Not just in chromosome segregation, but fused to diverse domains, often on mobile genetic elements.

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Tung Le @tunglejic.bsky.social · 1d

The first CTP switch? ParB, a bacterial DNA segregation protein.

ParB uses CTP to clamp around DNA, recruit ParA (an ATPase), and ensure chromosomes are properly inherited by daughter cells. CTP hydrolysis then recycles ParB. This represents a new regulatory principle!

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Tung Le @tunglejic.bsky.social · 1d

1/ Molecular switches are ubiquitous in biology.
One class of such switches bind nucleotide triphosphate (ATP, GTP, etc.), flip “on/off,” and regulate essential processes: growth, DNA replication, protein synthesis.
For decades, only GTPase/ATPase switches were known. Then came CTPases.

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Tung Le @tunglejic.bsky.social · 1d

new preprint from our group & Antoine Hocher: www.biorxiv.org/content/10.1...
A fantastic collaboration with Antoine, with Jovana Kaljevic' initiated the collaboration and drives the project.

Versatile NTP recognition and domain fusions expand the functional repertoire of the ParB-CTPase fold beyond chromosome segregation

Nucleotide triphosphate (NTP)-dependent molecular switches regulate essential cellular processes by cycling between active and inactive states through nucleotide binding and hydrolysis. These mechanis...

www.biorxiv.org

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Tung Le @tunglejic.bsky.social · 3d

Tung Le @tunglejic.bsky.social · 8d

Independent research fellowships leading to tenured positions at the John Innes Centre.

Repost = nice. Thank you very much!!!

John Innes Centre @johninnescentre.bsky.social · 8d

Shortlisted candidates will be invited to give a seminar at the Fellows Conference, which will be held on 10 March 2026.

Candidates who win Fellowships will be offered a Tenure Track Group Leader position from the outset, initially for 5 years.

Find out more: www.jic.ac.uk/training-car...

Tung Le @tunglejic.bsky.social · 5d

Tung Le @tunglejic.bsky.social · 8d

Independent research fellowships leading to tenured positions at the John Innes Centre.

Repost = nice. Thank you very much!!!

John Innes Centre @johninnescentre.bsky.social · 8d

Shortlisted candidates will be invited to give a seminar at the Fellows Conference, which will be held on 10 March 2026.

Candidates who win Fellowships will be offered a Tenure Track Group Leader position from the outset, initially for 5 years.

Find out more: www.jic.ac.uk/training-car...

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Reposted by Tung Le

Tung Le @tunglejic.bsky.social · 8d

Independent research fellowships leading to tenured positions at the John Innes Centre.

Repost = nice. Thank you very much!!!

John Innes Centre @johninnescentre.bsky.social · 8d

Shortlisted candidates will be invited to give a seminar at the Fellows Conference, which will be held on 10 March 2026.

Candidates who win Fellowships will be offered a Tenure Track Group Leader position from the outset, initially for 5 years.

Find out more: www.jic.ac.uk/training-car...

Independent Research Fellowships Leading to Tenured Faculty Positions | John Innes Centre

The John Innes Centre (JIC), is a world leading centre of excellence in plant and microbial sciences based on the Norwich Research Park, UK. We are inviting applications from outstanding researchers…

www.jic.ac.uk

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Reposted by Tung Le

Michael Webster @michaelwebster.bsky.social · 8d

Start independent research at the JIC with us 👇.

Really interested in finding those with an interest in structural biology and biochemistry of plants and microbes.

Please do get in touch by email if you'd like to know more 👍

John Innes Centre @johninnescentre.bsky.social · 8d

VACANCY - Independent research fellowships leading to tenured positions

We’re inviting applications from outstanding researchers who either hold, or wish to apply for, Independent Research Fellowships.

APPLICATION DEADLINE: 10 November 2025

Click here to apply: jic.link/Fellows

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Tung Le @tunglejic.bsky.social · 8d

John Innes Centre @johninnescentre.bsky.social · 8d

VACANCY - Independent research fellowships leading to tenured positions

We’re inviting applications from outstanding researchers who either hold, or wish to apply for, Independent Research Fellowships.

APPLICATION DEADLINE: 10 November 2025

Click here to apply: jic.link/Fellows

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Tung Le @tunglejic.bsky.social · 8d

Independent research fellowships leading to tenured positions at the John Innes Centre.

Repost = nice. Thank you very much!!!

John Innes Centre @johninnescentre.bsky.social · 8d

Shortlisted candidates will be invited to give a seminar at the Fellows Conference, which will be held on 10 March 2026.

Candidates who win Fellowships will be offered a Tenure Track Group Leader position from the outset, initially for 5 years.

Find out more: www.jic.ac.uk/training-car...

Independent Research Fellowships Leading to Tenured Faculty Positions | John Innes Centre

The John Innes Centre (JIC), is a world leading centre of excellence in plant and microbial sciences based on the Norwich Research Park, UK. We are inviting applications from outstanding researchers…

www.jic.ac.uk

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Reposted by Tung Le

Giusy Mariano @giusym1990.bsky.social · 10d

🚨PhD Opportunity Alert🚨 Join me, @suzieh.bsky.social and @walllabuoglasgow.bsky.social to investigate how environment shapes anti-phage defences & prophage–prophage conflict in Pseudomonas aeruginosa.
Apply here:
www.gla.ac.uk/postgraduate...

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Tung Le @tunglejic.bsky.social · 15d

Major advance here for our field!!!

Emmanuele Severi @emmseveri.bsky.social · 15d

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

#microsky

Molecular basis of ParA ATPase activation by the CTPase ParB during bacterial chromosome segregation - Nature Communications

ParABS systems partition chromosomal DNA and low-copy plasmids in bacteria. Here, the authors elucidate the mode of interaction between ParA and ParB and clarify how ParB stimulates the ATPase activity of ParA to drive the segregation process.

www.nature.com

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Reposted by Tung Le

Emmanuele Severi @emmseveri.bsky.social · 15d

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

#microsky

Molecular basis of ParA ATPase activation by the CTPase ParB during bacterial chromosome segregation - Nature Communications

ParABS systems partition chromosomal DNA and low-copy plasmids in bacteria. Here, the authors elucidate the mode of interaction between ParA and ParB and clarify how ParB stimulates the ATPase activity of ParA to drive the segregation process.

www.nature.com

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Tung Le @tunglejic.bsky.social · 15d

Xindan Wang has done a lot of Hi-C for Borrelia so she/her group has that skillset.

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Reposted by Tung Le

Renske van Raaphorst 🟥 @vrrenske.bsky.social · 16d

Jovana Kaljevic (now postdoc @tunglejic.bsky.social ) saw how extremely compact Bdello chromosomes are packed during the non-proliferative attack phase (see pmc.ncbi.nlm.nih.gov/articles/PMC... ). GFP is excluded from the nucleoid area! 2/n

Chromosome choreography during the non-binary cell cycle of a predatory bacterium

In bacteria, the dynamics of chromosome replication and segregation are tightly coordinated with cell-cycle progression and largely rely on specific spatiotemporal arrangement of the chromosome. Where...

pmc.ncbi.nlm.nih.gov

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Reposted by Tung Le

Renske van Raaphorst 🟥 @vrrenske.bsky.social · 16d

Happy to finally show our story of the connection between nucleoid conformation, transcription & predation in our favorite predator Bdellovibrio bacteriovorus. 🧵 1/n

Géraldine Laloux @lalouxlab.bsky.social · 17d

📝New preprint! #MicroSky

🕰️We chart the full, synchronized lifecycle of a predatory bacterium using Hi-C, RNA-seq, ChIP-seq & microscopy.

🧬We uncover dramatic shifts in nucleoid architecture & transcription, tightly coordinated with predation.

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

Dynamics and interplay of gene expression and chromosome organization across a predatory lifecycle

The obligate predatory bacterium Bdellovibrio bacteriovorus alternates between a motile attack phase and a growth phase inside another bacterium, during which it undergoes multiple rounds of DNA repli...

www.biorxiv.org

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Reposted by Tung Le

bioRxiv Microbiology @biorxiv-microbiol.bsky.social · 17d

Dynamics and interplay of gene expression and chromosome organization across a predatory lifecycle https://www.biorxiv.org/content/10.1101/2025.09.24.678257v1

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Tung Le @tunglejic.bsky.social · 17d

Very creative and clever!!!

bioRxivpreprint @biorxivpreprint.bsky.social · 19d

Dosa: A method to covalently barcode proteinsfor high throughput biochemistry https://www.biorxiv.org/content/10.1101/2025.09.21.677650v1

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Reposted by Tung Le

bioRxivpreprint @biorxivpreprint.bsky.social · 19d

Dosa: A method to covalently barcode proteinsfor high throughput biochemistry https://www.biorxiv.org/content/10.1101/2025.09.21.677650v1

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Tung Le @tunglejic.bsky.social · 18d

Many congratulations, Y and team!!!

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