title: Six GTP-binding proteins of the Era/Obg family are essential for cell growth in Bacillus subtilis.
abstract: GTP-binding proteins are found in all domains of life and are involved in various essential cellular processes. With the recent explosion of available genome sequence data, a widely distributed bacterial subfamily of GTP-binding proteins was discovered, represented by the Escherichia coli Era and the Bacillus subtilis Obg proteins. Although only a limited number of the GTP-binding proteins belonging to the subfamily have been experimentally characterized, and their function remains unknown, the available data suggests that many of them are essential to bacterial growth. When the complete genomic sequence of B. subtilis was surveyed for genes encoding GTP-binding proteins of the Era/Obg family, nine such genes were identified. As a first step in elucidating the functional networks of those nine GTP-binding proteins, data presented here indicates that six of them are essential for B. subtilis viability. Additionally, it is shown that the six essential proteins are able to specifically bind GTP and GDP in vitro. Experimental depletion of the essential GTP-binding proteins was examined in the context of cell morphology and chromosome replication, and it was found that two proteins, Bex and YqeH, appeared to participate in the regulation of initiation of chromosome replication. Collectively, these results suggest that members of the GTP-binding Era/Obg family are important proteins with precise, yet still not fully understood, roles in bacterial growth and viability.
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Takuya
authors.initials: T
authors.lastname: Morimoto
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Pek Chin
authors.initials: PC
authors.lastname: Loh
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Hirai
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Kei
authors.initials: K
authors.lastname: Asai
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Moriya
authors.affiliation: Department of Microbial Cell Biology, Graduate school of Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan1.
authors.forename: Naotake
authors.initials: N
authors.lastname: Ogasawara
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000254:growth & development* / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000145:classification; D002876:Chromosomes, Bacterial / Q000502:physiology; D029968:Escherichia coli Proteins; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000145:classification / Q000502:physiology*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016601:RNA-Binding Proteins; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C090542:Obg GTP-binding protein, Bacteria; D016601:RNA-Binding Proteins; C068027:era protein, E coli; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins