title: Tubulin homolog TubZ in a phage-encoded partition system.
abstract: Partition systems are responsible for the process whereby large and essential plasmids are accurately positioned to daughter cells during bacterial division. They are typically made of three components: a centromere-like DNA zone, an adaptor protein, and an assembling protein that is either a Walker-box ATPase (type I) or an actin-like ATPase (type II). A recently described type III segregation system has a tubulin/FtsZ-like protein, called TubZ, for plasmid movement. Here, we present the 2.3 Å structure and dynamic assembly of a TubZ tubulin homolog from a bacteriophage and unravel the Clostridium botulinum phage c-st type III partition system. Using biochemical and biophysical approaches, we prove that a gene upstream from tubZ encodes the partner TubR and localize the centromeric region (tubS), both of which are essential for anchoring phage DNA to the motile TubZ filaments. Finally, we describe a conserved fourth component, TubY, which modulates the TubZ-R-S complex interaction.
authors.affiliation: Centro de Investigaciones Biológicas-Consejo Superior de Investigaciones Cientificas, 28040 Madrid, Spain. marian@cib.csic.es
authors.forename: María A
authors.initials: MA
authors.lastname: Oliva
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Martin-Galiano
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sakaguchi
authors.forename: José M
authors.initials: JM
authors.lastname: Andreu
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism; D001435:Bacteriophages / Q000737:chemistry*; D001483:Base Sequence; D001703:Biophysics; D002503:Centromere / Q000378:metabolism; D003001:Cloning, Molecular; D003014:Clostridium botulinum / Q000502:physiology*; D016000:Cluster Analysis; D019295:Computational Biology; D003460:Crystallization; D048749:Cytokinesis / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes / Q000378:metabolism*; D010802:Phylogeny; D010957:Plasmids / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014404:Tubulin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D046912:Multiprotein Complexes; D014404:Tubulin; C052883:chromosome partition proteins, bacterial