title: Structure of Spo0M, a sporulation-control protein from Bacillus subtilis.
abstract: Spo0M is a sporulation-control protein that is thought to play an essential role in the early stage of endospore formation. While little is known about the functions of Spo0M, a recent phylogenetic study suggests that, based on its amino-acid sequence, Spo0M might belong to the arrestin clan. The crystal structure of the Spo0M protein was determined at a resolution of 2.3 Å. Ten amino acids at the end of the N-terminus were removed to improve the thermal stability of the purified Spo0M protein and the crystal structure of Spo0M was determined by SAD. Spo0M has a well conserved N-terminal domain with an arrestin-like fold, which consists of a β-strand sandwich structure. Surprisingly, the C-terminal domain of Spo0M, which has no structural homology to arrestin-clan proteins, bears significant structural similarity to the FP domain of the human PI31 protein. In addition, Spo0M harbours a potential polar-core structure connecting the N- and C-terminal domains with several salt bridges, as seen in the crystal structures of arrestin and VPS26. The structure reported here constitutes the first structural information on a bacterial protein that shares significant structural homology to members of the arrestin clan and the FP domain.
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Yo
authors.initials: Y
authors.lastname: Sonoda
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Kimihiko
authors.initials: K
authors.lastname: Mizutani
authors.affiliation: Laboratory of Applied Structural Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Bunzo
authors.initials: B
authors.lastname: Mikami
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000378:metabolism* / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002850:Chromatography, Gel; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D008970:Molecular Weight; D050505:Mutant Proteins / Q000737:chemistry; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013171:Spores, Bacterial / Q000378:metabolism; D040681:Structural Homology, Protein
chemical_list: D001426:Bacterial Proteins; D050505:Mutant Proteins; C115343:spo0M protein, Bacillus subtilis
keywords: FP domain; PI31; Spo0M; arrestin; sporulation-control protein