title: NMR structure of the heterodimer of Bem1 and Cdc24 PB1 domains from Saccharomyces cerevisiae.
abstract: Bem1 and Cdc24 of the budding yeast Saccharomyces cerevisiae interact with each other through PB1-PB1 heterodimer formation to regulate the establishment of cell polarity. Here we present the tertiary structure of the heterodimer of Bem1 and Cdc24 PB1 domains determined by NMR spectroscopy. To avoid ambiguity in the NMR spectral analysis, we first prepared a mutant of the Cdc24 PB1 domain that had truncated loops. The mutant provided well dispersed spectra without spectral overlapping, thus allowing unambiguous spectral assignments for structure determination. We confirmed that the loop deletion-mutant was quite similar to the wild-type in both 3D structure and binding affinity. The NMR structure of the heterodimer of the deletion-mutant of Cdc24 PB1 and Bem1 PB1 was determined using a variety of isotope labelled samples including perdeuteration. The interface between the Bem1/Cdc24 PB1 heterodimer was analysed at atomic resolution. Through a comparison with the tertiary structures of other PB1-PB1 heterodimers, we found that conserved electrostatic properties on the molecular surface were commonly used for PB1-PB1 interaction, but hydrophobic interactions were important for cognate interaction in Bem1/Cdc24 PB1 heterodimer formation.
authors.affiliation: Department of Structural Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 12 Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ogura
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Tandai
authors.forename: Sosuke
authors.initials: S
authors.lastname: Yoshinaga
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kobashigawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kumeta
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.forename: Hideki
authors.initials: H
authors.lastname: Sumimoto
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Inagaki
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000378:metabolism*; D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C073594:CDC24 protein, S cerevisiae; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D050505:Mutant Proteins; D029701:Saccharomyces cerevisiae Proteins; C073129:BEM1 protein, S cerevisiae