9RMI

Cryo-EM structure of the CorM filament in the presence of CorR from cyanobacterium Anabaena sp. PCC 7120

Summary for 9RMI

• Entry DOI: 10.2210/pdb9rmi/pdb
• EMDB information: 54060
• Descriptor: CorM, ADENOSINE-5'-DIPHOSPHATE (2 entities in total)
• Functional Keywords: cell shape, cytoskeleton, structural protein
• Biological source: Nostoc sp. PCC 7120 = FACHB-418
• Total number of polymer chains: 6
• Total formula weight: 250841.63

Authors

Springstein, B.L.,Javoor, M.G.,Megrian, D.,Hajdu, R.,Hanke, D.M.,Schur, F.K.M.,Loose, M. (deposition date: 2025-06-18, release date: 2026-04-08, Last modification date: 2026-04-29)

Primary citation

Springstein, B.L.,Javoor, M.G.,Megrian, D.,Hajdu, R.,Hanke, D.M.,Zens, B.,Weiss, G.L.,Schur, F.K.M.,Loose, M.
Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape.
Science, 392:eaea6343-eaea6343, 2026

PubMed Abstract: Bacteria, like eukaryotes, use conserved cytoskeletal systems for intracellular organization. The plasmid-encoded ParMRC system forms actin-like filaments that segregate low-copy number plasmids. In multicellular cyanobacteria such as sp., we found that a chromosomally encoded ParMR system has evolved into a cytoskeletal system named CorMR with a function in cell shape control rather than DNA segregation. Live-cell imaging, in vitro reconstitution, and cryo-electron microscopy revealed that CorM formed dynamically unstable, antiparallel double-stranded filaments that were recruited to the membrane by CorR through an amphipathic helix conserved in multicellular cyanobacteria. CorMR filaments were regulated by MinC, which excluded them from the poles and division plane. Comparative genomics indicated that the repurposing of ParMR and Min systems coevolved with cyanobacterial multicellularity, highlighting the evolutionary plasticity of cytoskeletal systems in bacteria.

PubMed: 41990175
DOI: 10.1126/science.aea6343

Experimental method

ELECTRON MICROSCOPY (3.92 Å)