article published yes Benjamin L Springstein author b4eb62ef-ac72-11ed-9503-ed3b4d66c0830000-0002-3461-5391 Manjunath Javoor author 305ab18b-dc7d-11ea-9b2f-b58195228ea20000-0003-2311-2112 Daniela Megrian author Roman Hajdu author ffab949d-133f-11ed-8f02-94de21ace503 Dustin M. Hanke author Bettina Zens author 45FD126C-F248-11E8-B48F-1D18A9856A870000-0002-9561-1239 Gregor L. Weiss author Florian Km Schur author 48AD8942-F248-11E8-B48F-1D18A9856A870000-0003-4790-8078 Martin Loose author 462D4284-F248-11E8-B48F-1D18A9856A870000-0001-7309-9724 MaLo department FlSc department GradSch department EM-Fac department IST-BRIDGE: International postdoctoral program project A molecular atlas of Actin filament IDentities in the cell motility machinery project 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 Anabaena 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. AAAS2026 eng 0036-8075 1095-9203 4199017510.1126/science.aea6343 3926795 B.L. Springstein, M. Javoor, D. Megrian, R. Hajdu, D.M. Hanke, B. Zens, G.L. Weiss, F.K. Schur, M. Loose, Science 392 (2026). Springstein, B. L., Javoor, M., Megrian, D., Hajdu, R., Hanke, D. M., Zens, B., … Loose, M. (2026). Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape. <i>Science</i>. AAAS. <a href="https://doi.org/10.1126/science.aea6343">https://doi.org/10.1126/science.aea6343</a> B. L. Springstein <i>et al.</i>, “Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape,” <i>Science</i>, vol. 392, no. 6795. AAAS, 2026. Springstein, Benjamin L, Manjunath Javoor, Daniela Megrian, Roman Hajdu, Dustin M. Hanke, Bettina Zens, Gregor L. Weiss, Florian KM Schur, and Martin Loose. “Repurposing of a DNA Segregation Machinery into a Cytoskeletal System Controlling Cell Shape.” <i>Science</i>. AAAS, 2026. <a href="https://doi.org/10.1126/science.aea6343">https://doi.org/10.1126/science.aea6343</a>. Springstein, Benjamin L., et al. “Repurposing of a DNA Segregation Machinery into a Cytoskeletal System Controlling Cell Shape.” <i>Science</i>, vol. 392, no. 6795, eaea6343, AAAS, 2026, doi:<a href="https://doi.org/10.1126/science.aea6343">10.1126/science.aea6343</a>. Springstein BL, Javoor M, Megrian D, et al. Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape. <i>Science</i>. 2026;392(6795). doi:<a href="https://doi.org/10.1126/science.aea6343">10.1126/science.aea6343</a> Springstein BL, Javoor M, Megrian D, Hajdu R, Hanke DM, Zens B, Weiss GL, Schur FK, Loose M. 2026. Repurposing of a DNA segregation machinery into a cytoskeletal system controlling cell shape. Science. 392(6795), eaea6343. 217622026-04-26T22:01:46Z2026-04-28T13:29:05Z