title: Identification of the substrate binding site in the N-terminal TBP-like domain of RNase H3.
abstract: Ribonuclease H3 from Bacillus stearothermophilus (Bst-RNase H3) has the N-terminal TBP-like substrate-binding domain. To identify the substrate binding site in this domain, the mutant proteins of the intact protein and isolated N-domain, in which six of the seventeen residues corresponding to those involved in DNA binding of TBP are individually mutated to Ala, were constructed. All of them exhibited decreased enzymatic activities and/or substrate-binding affinities when compared to those of the parent proteins, suggesting that the N-terminal domain of RNase H3 uses the flat surface of the β-sheet for substrate binding as TBP to bind DNA. This domain may greatly change conformation upon substrate binding.
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Seiko
authors.initials: S
authors.lastname: Miyashita
authors.forename: Takashi
authors.initials: T
authors.lastname: Tadokoro
authors.forename: Clement
authors.initials: C
authors.lastname: Angkawidjaja
authors.forename: Dong-Ju
authors.initials: DJ
authors.lastname: You
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Koga
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Takano
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kanaya
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D001411:Geobacillus stearothermophilus / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D012260:Ribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012313:RNA; D004247:DNA; D012260:Ribonucleases; C117079:ribonuclease HIII