Stable inheritance of the Streptomyces linear plasmid SCP1 by dual ParABS partition systems

Abstract. Low-copy-number plasmids often rely on dedicated maintenance mechanisms, such as partitioning systems, to ensure stable inheritance across genera

academic.oup.com

Stable inheritance of the Streptomyces linear plasmid SCP1 by dual ParABS partition systems

Abstract. Low-copy-number plasmids often rely on dedicated maintenance mechanisms, such as partitioning systems, to ensure stable inheritance across genera

academic.oup.com

shorturl.at

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...

nature.com

Repurposing a chromosome segregation ParB-CTPase fold into an ATPase toxin for contact-dependent growth inhibition in plant and animal pathogens

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

biorxiv.org

Repurposing a chromosome segregation ParB-CTPase fold into an ATPase toxin for contact-dependent growth inhibition in plant and animal pathogens

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

biorxiv.org

Early Career Microbiologists Mini-Symposium 2026 | John Innes Centre

The Department of Molecular Microbiology is organising a one and a half day Early- Career Microbiologists Mini-Symposium. The symposium will be held from Tuesday 22nd – Wednesday 23rd September 2026.

jic.ac.uk

Primary metabolic enzymes in antibiotic-producing Streptomyces bacteria, but not as we know them! at University of Strathclyde on FindAPhD.com

PhD Project - Primary metabolic enzymes in antibiotic-producing Streptomyces bacteria, but not as we know them! at University of Strathclyde, listed on FindAPhD.com

findaphd.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents - Nature Microbiology

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 ...

nature.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents - Nature Microbiology

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 ...

nature.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents

Nature Microbiology, Published online: 16 April 2026; doi:10.1038/s41564-026-02316-4An 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 horizontal gene transfer.

go.nature.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents - Nature Microbiology

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 ...

nature.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents - Nature Microbiology

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 ...

nature.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents - Nature Microbiology

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 ...

nature.com

A bacterial CARD–NLR-like immune system controls the release of gene transfer agents - Nature Microbiology

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 ...

nature.com

Meet the 2026 Marjory Stephenson Prize Winner, Professor Mark Buttner

Ahead of the 2026 Marjory Stephenson Prize Lecture, Omolulu Fagunwa interviewed Professor Mark Buttner to learn more about his career and how it feels to win a Microbiology Society prize.

microb.io

biorxiv.org

Polyphosphate acts as an architectural regulator of carbon fixation and nucleoid structure in cyanobacteria

Polyphosphate (polyP) is a conserved inorganic polymer traditionally viewed as a stress-induced phosphate and energy reserve. In cyanobacteria, however, polyP granules are constitutively present and frequently observed in proximity to carboxysomes, the bacterial microcompartments that mediate CO2 fixation. Here we show that polyP functions as a spatially organized regulator of the photosynthetic cytoplasm in Synechococcus elongatus. PolyP granules localize to the nucleoid and are periodically arranged along the cell axis, independently of the McdAB carboxysome positioning system. Despite this independence, polyP and carboxysomes associate non-randomly, and this association is enhanced when active carboxysome positioning by the McdAB system is disrupted. Loss of polyP synthesis leads to nucleoid expansion, an increased number of smaller carboxysomes with high mobility, and severe defects in growth under ambient CO2. Perturbation of polyP turnover further reveals structural connections to both carboxysomes and thylakoid membranes. Together, these findings identify polyP as an architectural integrator that couples chromosome organization, metabolic compartmentalization, and photosynthetic fitness. ### Competing Interest Statement The authors have declared no competing interest. National Institute of General Medical Sciences, https://ror.org/04q48ey07, R01-GM144731, R35-GM152128 Howard Hughes Medical Institute

biorxiv.org

Advancing microbiology through foundational science - Nature Microbiology

Microorganisms have tremendous potential to impact humanity, but such revelations are only possible in the light of foundational, discovery-based microbiology research.

nature.com

MGE-UK-4

We are thrilled to invite you to the fourth edition of the MGE UK Workshop, hosted this year in the historic City of York. Mobile Genetic Elements (MGEs) are the ultimate architects of biology. MGEs i...

ukmgeworkshop.org