8R2N

Structure of the BeeR filament

Summary for 8R2N

• Entry DOI: 10.2210/pdb8r2n/pdb
• EMDB information: 18852
• Descriptor: Actin/actin family protein, ADENOSINE-5'-TRIPHOSPHATE, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: bacterial cytoskeleton, actin homologue, structural protein
• Biological source: Opitutus terrae
• Total number of polymer chains: 12
• Total formula weight: 499825.61

Authors

Bergeron, J.R.C.,Kollman, J.M. (deposition date: 2023-11-07, release date: 2025-03-05, Last modification date: 2025-03-26)

Primary citation

Bergeron, J.R.C.,Lale-Farjat, S.L.M.,Lewicka, H.M.,Parry, C.,Kollman, J.M.
A family of bacterial actin homologs forms a three-stranded tubular structure.
Proc.Natl.Acad.Sci.USA, 122:e2500913122-e2500913122, 2025

PubMed Abstract: The cytoskeleton is crucial for cell organization and movement. In Eukaryotes, it largely consists of the protein actin, that forms a double-stranded linear filamentous structure in the presence of ATP and disassemble upon ATP hydrolysis. Bacteria also possess actin homologs, that drive fundamental cellular processes, including cell division, shape maintenance, and DNA segregation. Like eukaryotic actin, bacterial actins assemble into dynamic polymers upon ATP binding, however variation in interactions between strands gives rise to striking diversity of filament architectures. Here, we report a family of bacterial actins of unknown function, conserved among the phylum, which assembles into a unique tubular structure in the presence of ATP. A cryo-EM structure of the filaments reveals that it consists of three strands, unlike other described bacterial actin structures. This architecture provides further insights into the organization of actin-like filaments and has implications for understanding the diversity and evolution of the bacterial cytoskeleton.

PubMed: 40073056
DOI: 10.1073/pnas.2500913122

Experimental method

ELECTRON MICROSCOPY (3.1 Å)