Justin Di Trani

Discovery of inhibitors of the Pseudomonas aeruginosa NADH:ubiquinone oxidoreductase (NQR) that hinder virulence factors The growing threat of antimicrobial resistance has created an urgent need to identify novel therapeutic targets in bacteria. The NADH:ubiquinone oxidoreductase (NQR) is a potential target in a number of bacteria that transfers electrons from NADH to ubiquinone while pumping ions from the cytoplasm to the periplasm. In most species, this complex pumps sodium ions, whereas in Pseudomonas aeruginosa it pumps protons, thereby functioning as a member of the electron transport chain. Using a strain of PAO1 with the NQR knocked out, we demonstrate that the NQR complex plays a crucial role in the motility and biofilm development virulence factors in P. aeruginosa. We develop and execute a high-throughput inhibitor screen to identify and confirm compounds that inhibit NADH oxidation by this complex. Using single-particle cryogenic electron microscopy (cryoEM), we determine high-resolution structures of the NQR complex, both inhibitor-free and bound to one of the confirmed hits from our screen, demonstrating that it binds to the ubiquinone binding site. These structures provide insight into conformational dynamics controlled by binding at the ubiquinone site, with potential implications for the coupling between electron transfer and proton pumping in this complex. Biofilm development and motility assays with selected compounds from the screen show that they affect these virulence factors similarly to the NQR knockout. ### Competing Interest Statement The authors have declared no competing interest. Cystic Fibrosis Canada, https://ror.org/05b6dcx13 LKSIoV and University of Alberta Faculty of Medicine and Dentistry Startup funding Striving for Pandemic Preparedness – The Alberta Research Consortium Canada Research Chairs Canadian Institutes of Health Research, https://ror.org/01gavpb45 LKSIoV Research Support and Innovation Grant

In the first preprint from the lab, @sandaru-ileperuma.bsky.social demonstrates that the P. aeruginosa NQR complex supports virulence factors and identifies inhibitors of this complex. He also uncovered some interesting NQR dynamics controlled at the substrate binding site. tinyurl.com/yush599n

Conformational changes in the motor ATPase CpaF facilitate a rotary mechanism of Tad pilus assembly - Nature Communications The bacterial Tad pilus extends and retracts using a single bifunctional ATPase CpaF. Here, the authors employ cryo-EM, fluorescent microscopy, and AlphaFold modelling to propose how a rotary mechanis...

Thrilled to announce my first PhD publication in Nature Comms! We determined structures of the Tad pilus ATPase CpaF from Caulobacter. We use these structures to propose how CpaF employs a rotary mechanism of catalysis to drive Tad pilus assembly.
www.nature.com/articles/s41...

Structure of Mycobacterial NDH-2 Bound to a 2-Mercapto-Quinazolinone Inhibitor Mycobacterial type II NADH dehydrogenase (NDH-2) is a promising drug target because of its central role in energy metabolism in Mycobacterium tuberculosis and other pathogens, and because it lacks a k...

Now published J. Med. Chem! @zestytoast.bsky.social's structure of type II NADH dehydrogenase from mycobacteria. A promising drug target for TB & other mycobacterial infections, Yingke demonstrates how an inhibitor can block transfer of electrons from NADH to the ETC.
pubs.acs.org/doi/full/10....

Public domain photo of Banff national park in Alberta, Canada.

🚨 Amazing Opportunity 🚨
U Alberta is looking for a director for their new #cryoEM facility
Support excellent researchers (who are really nice people) using state-of-the-art infrastructure.
+ reasonable cost of living
+ near some of most beautiful places in world
+ 🇨🇦
apps.ualberta.ca/careers/post...

Cryo-EM map and atomic model of the RAVE complex (regulator of ATPases of endosomes and vacuoles) bound to a partial V1-ATPase complex

Atomic model showing that the RAVE complex binds to a region of the V1 complex subunit A not found in the homologous ATP synthase subunit beta.

Most protein complexes are born only once. V-ATPase assembles over and over as part of its regulatory mechanism, enabled by RAVE (regulator of ATPase of vacuoles and endosomes)
@hanlinw222.bsky.social's 1st struct of RAVE bound to a partial V1 complex now out in PNAS.
www.pnas.org/doi/10.1073/...