The periplasmic and cytoplasmic faces of septal protein SepJ from filamentous cyanobacteria

Journal of Bacteriology, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

ABSTRACT Filamentous, N 2 -fixing, heterocyst-forming cyanobacteria grow as chains of cells in which intercellular transfer regulators and metabolites takes place, allowing them to behave multicellular organisms. Intercellular occurs by diffusion through septal junctions. In the model cyanobacterium Anabaena sp. strain PCC 7120, some identified proteins, including FraC FraD, are directly involved formation junctions that have been visualized cryo-electron tomography, whereas role key protein SepJ remains elusive. can form tetramers contains coiled-coil, linker, integral membrane (permease) domains. Using AlphaFold 3, a tetramer is predicted quaternary structure coiled-coil domain traverses cytoplasmic cavity formed between four permease Part thus located periplasm, where it interact with peptidoglycan. This possible be widespread filamentous explains known properties SepJ. Structures other proteins SjcF1, SepI, SepT could also consistent their previously described interactions. A interaction catalytic cell wall amidase AmiC1, would relevant prevent filament fragmentation , discussed. The renewed view presented here offers molecular basis for understanding this communication.

Language: Английский

Bacterial peptidoglycan recycling

Trends in Microbiology, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 1, 2024

Language: Английский