title: Crystal structure of the protein serine/threonine phosphatase 2C at 2.0 A resolution.
abstract: Protein phosphatase 2C (PP2C) is a Mn2+- or Mg2+-dependent protein Ser/Thr phosphatase that is essential for regulating cellular stress responses in eukaryotes. The crystal structure of human PP2C reveals a novel protein fold with a catalytic domain composed of a central beta-sandwich that binds two manganese ions, which is surrounded by alpha-helices. Mn2+-bound water molecules at the binuclear metal centre coordinate the phosphate group of the substrate and provide a nucleophile and general acid in the dephosphorylation reaction. Our model presents a framework for understanding not only the classical Mn2+/Mg2+-dependent protein phosphatases but also the sequence-related domains of mitochondrial pyruvate dehydrogenase phosphatase, the Bacillus subtilus phosphatase SpoIIE and a 300-residue domain within yeast adenyl cyclase. The protein architecture and deduced catalytic mechanism are strikingly similar to the PP1, PP2A, PP2B family of protein Ser/Thr phosphatases, with which PP2C shares no sequence similarity, suggestive of convergent evolution of protein Ser/Thr phosphatases.
authors.affiliation: Laboratory of Molecular Biophysics, University of Oxford, UK.
authors.forename: A K
authors.initials: AK
authors.lastname: Das
authors.forename: N R
authors.initials: NR
authors.lastname: Helps
authors.forename: P T
authors.initials: PT
authors.lastname: Cohen
authors.forename: D
authors.initials: D
authors.lastname: Barford
mesh_terms: D000262:Adenylyl Cyclases / Q000737:chemistry; D000595:Amino Acid Sequence; D002384:Catalysis; D018360:Crystallography, X-Ray; D006801:Humans; D007150:Immunohistochemistry; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D011487:Protein Conformation; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D008345:Manganese; C000607456:PPM1A protein, human; C000607457:PPM1B protein, human; C000607460:PPM1G protein, human; C087358:PTC1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D000071636:Protein Phosphatase 2C; D000262:Adenylyl Cyclases; D008274:Magnesium