Debnath Ghosal

Thank you so much Kate

Beautiful work Deb! Check out these structures? Biofilms are very interesting. 🧶🧬

Great collaboration with #ZavialovLab, #UhlinLab and #KnightLab. And terrific effort from our PhD student
@bindusmitapaul.bsky.social @UniMelb @CCeMMP, @UniMelbMDHS, @CGCPT. Of course, #HenriMalmi and #NataliaPakharukova are two superstars who led this project!

Cryo-EM structures of individual pilus, pilus pairs, and multi-pilus stacks revealed the structural framework of 3D biofilms, informing novel therapeutic strategies. 🦠🔬

We used electron cryo-tomography to reveal that an extensive network of thin bacterial filaments (Csu pilus/pili) forms a flat, stacked meshwork that mediates cell–cell connections and assembles drug-resistant biofilms.

Antiparallel stacking of Csu pili drives Acinetobacter baumannii 3D biofilm assembly - PubMed Many Gram-negative nosocomial pathogens rely on adhesive filaments, known as archaic chaperone-usher pili, to establish stress- and drug-resistant, multi-layered biofilms. Here, we uncover the mechanism by which these pili build three-dimensional (3D) biofilm architectures. In situ analyses of Acine …

A. baumannii is one of the most notorious multidrug-resistant pathogens, capable of forming drug-tolerant biofilms that make infections exceptionally difficult to treat. But how are these complex microbial fortresses built? Just published in Nat Comms. pubmed.ncbi.nlm.nih.gov/41654547/

Many thanks @arianebriegel.bsky.social :-)

🌀 How do spirochete bacteria swim through thick fluids like champions?

We solved T. denticola flagella structure - asymmetric proteins expand one side, compress the other for perfect corkscrew motion!

@debnathghosal.bsky.social

🔗 doi.org/10.64898/202...

#StructuralBiology #CryoEM #Microbiology

Wonderful collaboration with #EricReynolds, #JillBanfield, and #ChrisFenno labs. Terrific effort from @lucatroman.bsky.social who drove the high-resolution work, great support from @bindusmitapaul.bsky.social and #JackKim, @CCeMMP, @UniMelbMDHS, @CGCPT.

🧬 Comparative analysis shows that FlaL proteins are conserved across several spirochetes, suggesting that asymmetric assembly is a modular solution to the mechanical demands of periplasmic flagella, providing a new structural framework for bacterial motility.

Different sheath proteins do different jobs. • FlaA1 expands the lattice on the outer curve • FlaA2/3 compress the inner curve. • FlaL1 🧩 & FlaL2 🧩 stabilize this asymmetric architecture. All of these proteins wrap around the core formed by FlaB.

Using visual proteomics (powered by AI-based ModelAngelo), we show that T. denticola flagellar filament is composed of 7 different proteins, including 2 novel ¬– flagellar lattice proteins FlaL1 and FlaL2, making this one of the most complex bacterial filament systems.

The secret is asymmetry. A conserved FlaB core is wrapped by multiple sheath proteins that decorate the filament unevenly, breaking symmetry and imposing curvature. Basically, structure → mechanics → motion! 🤯

❄️ 🔬 Using near-atomic resolution cryo-EM and visual proteomics, we solved native flagellar filament structures from Treponema denticola, a major oral pathogen. What we found is remarkable!

🦠 Spirochetes cause many diseases e.g., syphilis, Lyme disease, and periodontitis. They twist their cell body to move through viscous environments. The engine? Curved periplasmic flagella. How do they bend their flagella to drill through tissue?

📣 New paper alert! This is a story of molecular tricks that let spirochetes (spiral-shaped bacteria) drill through tissue. www.biorxiv.org/content/10.6...

Congratulations!

Wow! Mind boggling! How long did it take? Many congratulations!

Fantastic MEL-JPN workshop on the intersections between #bacteria and #mitochondria at #Bio21 (very nice lunchtime too). Organized by Takuya Shiota and Rhys Grinter

I have one in my office too!

Nice work @arianebriegel.bsky.social

Last week we had the CCeMMP Symposium 2025. Fantastic event with an outstanding line-up of speakers. There were 2 poster prizes and 1 oral presentation prize; thrilled that we did a clean sweep! Huge congratulations @tiltedscientist.bsky.social @somavallyd.bsky.social and @lucatroman.bsky.social

Great stuff @joshuamhardy.bsky.social ! Congratulations.

A Protein Antibiotic Inhibits the BAM Complex to Kill Without Cell Entry Many antibiotics are ineffective against Gram-negative pathogens such as Pseudomonas aeruginosa because they cannot penetrate the bacterial outer membrane. Here, we show that protein antibiotics calle...

This is an amazing paper led by the Grinter lab on bacterial protein antibiotics called pyocins and the mechanism by which they inhibit the BAM outer membrane complex. @rhyswg.bsky.social, @knottrna.bsky.social, @debnathghosal.bsky.social, @doylemt1.bsky.social, @fabianmunder.bsky.social

Incredible!

We recently discovered a brand-new (and unique!) anti-phage defense system in bacteria. Check out this Pursuit article from @Melbourne University featuring our recent work. Terrific effort from our PhD student Somavally!

lnkd.in/geXUApmK

3 months, 3 thesis orations: a hat-trick moment for the lab!! 🎓🥳.
This time, Bindusmita in the spotlight! ✨ She delivered a fantastic thesis oration, packed with fascinating data and insights 🦠 ❄️ 🔬. It has been an absolute joy mentoring her. Huge congratulations @bindusmitapaul.bsky.social

Insights into type IX secretion from PorKN cogwheel structure bound to PorG and attachment complexes - Nature Communications Type IX secretion system (T9SS) is required for protein export in the Bacteroidota. Here, the authors obtain structure of T9SS PorKN ring which resembles a cogwheel that may have a rotational movement...

My longest ever running project, all the stars finally aligned after 13 years! Thank you to Eric Reynolds group for sharing the journey. #bio21-institute, #university-of-melbourne. @sepidehv.bsky.social @craigmorton.bsky.social @debnathghosal.bsky.social

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

Super cool work! Congratulations!

Our collaborative work on the T9SS is just out in Nature Communications! Fantastic work led by Dhana Gorasia and Eric Hanssen. This paper reveals the structure of the T9SS outer membrane PorKN ring complex and mechanistic insights into protein secretion. www.nature.com/articles/s41...