title: Mutagenesis of apyrase conserved region 1 alters the nucleotide substrate specificity.
abstract: Two apyrases having different substrate specificity, MP67 and MpAPY2, are present in Mimosa pudica. The substrate specificity of MP67 is quite high against ADP, and is distinct from any other apyrase. This might be attributed to the nucleotide binding motif (DXG) in apyrase conserved region 1. We performed a single amino acid substitution at position X in the motif. The ratio of the velocity of ATP/ADP hydrolysis was higher (approximately 1) for the S63A-MP67 mutant than for wild type-MP67 (0.19). Binding affinity for ADP of A75S-MpAPY2 mutant was increased to a level higher than that of the wild type MpAPY2. Thus, the residue at position X in the DXG motif plays an important role in determining nucleotide preference.
authors.affiliation: Department of Materials and Life Science; Faculty of Science and Technology; Sophia University; Tokyo, Japan.
authors.forename: Riku
authors.initials: R
authors.lastname: Okuhata
authors.forename: Yuki
authors.initials: Y
authors.lastname: Otsuka
authors.forename: Takahide
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kanzawa
mesh_terms: D000595:Amino Acid Sequence; D001081:Apyrase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D006868:Hydrolysis; D007700:Kinetics; D031298:Mimosa / Q000201:enzymology*; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000235:genetics*; D009711:Nucleotides / Q000378:metabolism*; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D009711:Nucleotides; D001081:Apyrase