Membrane binding of a cyanobacterial ESCRT-III protein crucially involves the helix α1-3 hairpin conserved in all superfamily members.

ABSTRACT: IM30, the inner membrane-associated protein of 30 kDa (also known as Vipp1) is essential for thylakoid membrane biogenesis and/or maintenance in chloroplasts and cyanobacteria. IM30 and its bacterial homolog PspA belong to the ESCRT-III superfamily, proteins previously thought to be restricted to eukaryotes and archaea. Despite low sequence similarity, IM30 shares key structural and functional features with eukaryotic ESCRT-IIIs, including a conserved α1-α2 helical hairpin core and the ability to form oligomeric barrel or rod assemblies that mediate membrane remodeling. Using IM30 variants, we now show that membrane binding of IM30 is driven by electrostatic interactions between the positively charged α1-α3 helical hairpin and negatively charged lipid surfaces, paralleling the role of char

SUBMITTER: Schlosser L 

PROVIDER: S-EPMC12636044 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature