title: Isolation of SIP, a protein that interacts with SPB, a possible transcriptional regulatory factor in Rhodobacter sphaeroides.
abstract: SPB is a transcriptional factor in Rhodobacter sphaeroides that represses expression of the puf operon under aerobic or semi-aerobic light conditions. Here, we identified a 17,500 Da protein designated SIP (SPB interaction protein) that interacts with SPB, as determined by binding to an SPB-His(x6) fusion protein-Ni column. The SPB-SIP interaction in vivo was confirmed by an immunoprecipitation assay. The level of transcripts and protein of SIP did not differ for all growth conditions tested, indicating that regulation of the SIP-SPB interaction, if any, is not through modulation of sip or spb expression but rather by modification of the proteins.
authors.affiliation: Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259, Nagatsuta-cho, Midori-ku, Yokohama, Japan. hshimada@bio.titech.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shimada
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ishida
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Machiya
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Takamiya
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D010788:Photosynthesis; D012242:Rhodobacter sphaeroides / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors