title: Enzymatic characteristics of an ApaH-like phosphatase, PrpA, and a diadenosine tetraphosphate hydrolase, ApaH, from Myxococcus xanthus.
abstract: We characterized the activities of the Myxococcus xanthus ApaH-like phosphatases PrpA and ApaH, which share homologies with both phosphoprotein phosphatases and diadenosine tetraphosphate (Ap4A) hydrolases. PrpA exhibited a phosphatase activity towards p-nitrophenyl phosphate (pNPP), tyrosine phosphopeptide and tyrosine-phosphorylated protein, and a weak hydrolase activity towards ApnA and ATP. In the presence of Mn(2+), PrpA hydrolyzed Ap4A into AMP and ATP, whereas in the presence of Co(2+) PrpA hydrolyzed Ap4A into two molecules of ADP. ApaH exhibited high phosphatase activity towards pNPP, and hydrolase activity towards ApnA and ATP. Mn(2+) was required for ApaH-mediated pNPP dephosphorylation and ATP hydrolysis, whereas Co(2+) was required for ApnA hydrolysis. Thus, PrpA and ApaH may function mainly as a tyrosine protein phosphatase and an ApnA hydrolase, respectively.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Department of Bioscience and Biotechnology, Kyusyu University, Hakozaki, Higashi-ku, Fukuoka, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takegawa
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa, Japan. Electronic address: kimura@ag.kagawa-u.ac.jp.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kimura
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000737:chemistry*; D000249:Adenosine Monophosphate / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D017124:Conserved Sequence; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016941:Myxococcus xanthus / Q000201:enzymology*; D009596:Nitrophenols / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry; D010748:Phosphopeptides / Q000737:chemistry; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000235:genetics; D013379:Substrate Specificity; D014443:Tyrosine / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D009596:Nitrophenols; D009943:Organophosphorus Compounds; D010748:Phosphopeptides; C008644:nitrophenylphosphate; D000249:Adenosine Monophosphate; D014443:Tyrosine; D000255:Adenosine Triphosphate; D010744:Phosphoric Monoester Hydrolases; D017766:Acid Anhydride Hydrolases; C075829:diadenosine polyphosphate hydrolase
keywords: Ap(n)A; ApaH-like phosphatase; Diadenosine polyphosphate hydrolase; Myxococcus xanthus; Protein phosphatase