title: Novel actin filaments from Bacillus thuringiensis form nanotubules for plasmid DNA segregation.
abstract: Here we report the discovery of a bacterial DNA-segregating actin-like protein (BtParM) from Bacillus thuringiensis, which forms novel antiparallel, two-stranded, supercoiled, nonpolar helical filaments, as determined by electron microscopy. The BtParM filament features of supercoiling and forming antiparallel double-strands are unique within the actin fold superfamily, and entirely different to the straight, double-stranded, polar helical filaments of all other known ParMs and of eukaryotic F-actin. The BtParM polymers show dynamic assembly and subsequent disassembly in the presence of ATP. BtParR, the DNA-BtParM linking protein, stimulated ATP hydrolysis/phosphate release by BtParM and paired two supercoiled BtParM filaments to form a cylinder, comprised of four strands with inner and outer diameters of 57 Å and 145 Å, respectively. Thus, in this prokaryote, the actin fold has evolved to produce a filament system with comparable features to the eukaryotic chromosome-segregating microtubule.
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore;
authors.forename: Shimin
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Structural Biology Research Center and Division of Biological Sciences, Nagoya University Graduate School of Science, Structural Biology Research Center and Division of Biological Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan; Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan;
authors.forename: Akihiro
authors.initials: A
authors.lastname: Narita
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore; rrobinson@imcb.a-star.edu.sg dpopp@imcb.a-star.edu.sg.
authors.forename: David
authors.initials: D
authors.lastname: Popp
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore;
authors.forename: Umesh
authors.initials: U
authors.lastname: Ghoshdastider
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore;
authors.forename: Lin Jie
authors.initials: LJ
authors.lastname: Lee
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Republic of Singapore; National Institute of Science, Education and Research, Bhubaneswar, Orissa 751005, India;
authors.forename: Ramanujam
authors.initials: R
authors.lastname: Srinivasan
authors.affiliation: Mechanobiology Institute, National University of Singapore, Singapore 117411, Republic of Singapore; Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117604, Republic of Singapore; Warwick Medical School, University of Warwick, Coventry CV4 7AL, England;
authors.forename: Mohan K
authors.initials: MK
authors.lastname: Balasubramanian
authors.affiliation: Tokai Gakuin University, Gifu 504-8511, Japan;
authors.forename: Toshiro
authors.initials: T
authors.lastname: Oda
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore;
authors.forename: Fujiet
authors.initials: F
authors.lastname: Koh
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore; Department of Medical Biochemistry and Microbiology, Uppsala University, SE-75123 Uppsala, Sweden;
authors.forename: Mårten
authors.initials: M
authors.lastname: Larsson
authors.affiliation: Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore; Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Republic of Singapore rrobinson@imcb.a-star.edu.sg dpopp@imcb.a-star.edu.sg.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Robinson
mesh_terms: D000199:Actins / Q000378:metabolism*; D001413:Bacillus thuringiensis / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics; D043942:Nanotubes; D010957:Plasmids
chemical_list: D000199:Actins; D004269:DNA, Bacterial; D049452:Green Fluorescent Proteins
keywords: ParM; actin; filament; microtubule; plasmid