@biorxiv-microbiol.bsky.social
Who knew ParB-CTPase fold can kill!!!
A protein fold best known for segregating chromosomesβ¦can be transformed into a potent antibacterial toxin in some plant and animal pathogens.
www.biorxiv.org/content/10.6...
Bacterial competition drives the evolution of antibacterial mechanisms, yet how new activities arise remains poorly understood. A major route to innovation is the reuse of pre-existing genetic systems, whereby conserved protein modules are repurposed in new biological contexts to generate new capabilities. Here, we show that the ParB-CTPase fold, a conserved nucleotide-binding module best known for its role in chromosome segregation, can be functionally repurposed as an antibacterial toxin. We identify ToxB, a ParB-like domain embedded within the polymorphic toxin region of contact-dependent inhibition systems and show that it functions as a potent antibacterial effector. Structural and biochemical analyses reveal that ToxB retains the core architecture of the ParB-CTPase fold but lacks DNA-binding capability and preferentially binds ATP. This shift in nucleotide specificity underpins a distinct mode of action, in which ATP binding and hydrolysis trigger rapid nucleoid compaction, chromosome segregation defects, oxidative stress, cell chaining, and ultimately cell lysis. ToxB also exhibits toxic activity in plant cells, suggesting that it targets conserved cellular processes. Together, these findings provide direct experimental evidence that the ParB-NTPase fold is biologically versatile and can be repurposed for biological roles fundamentally distinct from its ancestral function in DNA segregation. ### Competing Interest Statement The authors have declared no competing interest. Wellcome Trust, https://ror.org/029chgv08, 221776/Z/2/Z, 227755/Z/23/Z Biotechnology and Biological Sciences Research Council, https://ror.org/00cwqg982, BB/X01097X/1 Diamond Light Source, MX32728www.biorxiv.org
My second postdoc paper in @tunglejic.bsky.social lab and two of my favorite things in the lab combined: ParB and killing bacteria. Thanks to everyone who helped make this project possible!
Delighted to share our latest work on gene transfer agents (GTAs). We found a lysis control hub which allows GTAs to escape their bacterial host cells and transfer DNA 𧬠between bacteria. Thanks to @tunglejic.bsky.social, all co-authors, and our amazing collaborators!
www.nature.com/articles/s41...
Excited to share this is now published in @narjournal.bsky.social π see the preprint thread below for a summary of our findings on plasmids with multiple partition systems using the Streptomyces plasmid SCP1 as a model! academic.oup.com/nar/article/...
Come do a PhD with me and @trevor-lithgow.bsky.social at @monashuniversity.bsky.social ! Weβre at the leading edge of pathogen biology using cutting edge Cryo-EM and AI-driven genetic screens to uncover the mysteries of outer membrane biology. Reach out to me for a chat!
macsys.org/phd-scholars...
An immunity-like system functions as a lysis control hub to promote gene transfer agent particle release from host bacterial cells, suggesting that bacterial immune systems may be co-opted to promote ...www.nature.com
Very happy to see this remarkable work published. Led by @tommclean.bsky.social and @ainsley-beaton.bsky.social. We show how Streptomyces bacteria sense & respond to misfolded secreted proteins. A great collaboration with @barriewilks.bsky.social
#microsky
1/2
journals.asm.org/doi/epub/10....
Here, @tommclean.bsky.social shows that another RK2 regulator, TrbA, likely also use this βclamp sliding-lockingβ mechanism to regulate gene expression. Interesting how a single sliding clamp might integrate multiple partners to potentially build a complex regulatory network...
shorturl.at/YQJOI
@biorxiv-microbiol.bsky.social
Who knew ParB-CTPase fold can kill!!!
A protein fold best known for segregating chromosomesβ¦can be transformed into a potent antibacterial toxin in some plant and animal pathogens.
www.biorxiv.org/content/10.6...
Do cutting-edge research at the intersection of cryoβEM, genome-wide profiling, and AI-driven modelling. Work with worldβclass cryo-EM/cryo-ET imaging and AI tools to discover how the dangerous bacter...
now published!!! @johninnescentre.bsky.social @leahmcphillips.bsky.social
academic.oup.com/nar/article/...
Jovana KaljeviΔ β¬οΈ
Abstract. Low-copy-number plasmids often rely on dedicated maintenance mechanisms, such as partitioning systems, to ensure stable inheritance across genera
Delighted to see the main work from my PhD finally published in @mbio.bsky.social! It all started with the observation that deleting the cutRS two-component system in S. venezuelae caused this amazing explorer phenotype in the presence of glucose. But what was going on?! (1/n)
shorturl.at
Bacterial competition drives the evolution of antibacterial mechanisms, yet how new activities arise remains poorly understood. A major route to innovation is the reuse of pre-existing genetic systems, whereby conserved protein modules are repurposed in new biological contexts to generate new capabilities. Here, we show that the ParB-CTPase fold, a conserved nucleotide-binding module best known for its role in chromosome segregation, can be functionally repurposed as an antibacterial toxin. We identify ToxB, a ParB-like domain embedded within the polymorphic toxin region of contact-dependent inhibition systems and show that it functions as a potent antibacterial effector. Structural and biochemical analyses reveal that ToxB retains the core architecture of the ParB-CTPase fold but lacks DNA-binding capability and preferentially binds ATP. This shift in nucleotide specificity underpins a distinct mode of action, in which ATP binding and hydrolysis trigger rapid nucleoid compaction, chromosome segregation defects, oxidative stress, cell chaining, and ultimately cell lysis. ToxB also exhibits toxic activity in plant cells, suggesting that it targets conserved cellular processes. Together, these findings provide direct experimental evidence that the ParB-NTPase fold is biologically versatile and can be repurposed for biological roles fundamentally distinct from its ancestral function in DNA segregation. ### Competing Interest Statement The authors have declared no competing interest. Wellcome Trust, https://ror.org/029chgv08, 221776/Z/2/Z, 227755/Z/23/Z Biotechnology and Biological Sciences Research Council, https://ror.org/00cwqg982, BB/X01097X/1 Diamond Light Source, MX32728
Abstract. Low-copy-number plasmids often rely on dedicated maintenance mechanisms, such as partitioning systems, to ensure stable inheritance across genera
π Delighted to share that the preprint of my main PhD work is out now!
π A huge thank you to everyone involved, @tommclean.bsky.social, Govind Chandra, Ngat Tran (both not on BlueSky) and especially my PhD supervisor @tunglejic.bsky.social π
𧡠below!
www.biorxiv.org/content/10.6...
www.biorxiv.org
Low-copy-number plasmids often rely on dedicated maintenance mechanisms, such as partitioning systems, to ensure stable inheritance across generations. These partition systems actively segregate siste...
