title: Pterin-4a-carbinolamine dehydratase from Pseudomonas aeruginosa: characterization, catalytic mechanism and comparison to the human enzyme.
abstract: The three-dimensional structure of pterin-4a-carbinolamine dehydratase (PCD) from Pseudomonas aeruginosa has been solved. Based on this we have investigated the roles of putative active center residues through functional replacement by site-directed mutagenesis. Three histidines, His73, His74 and His91, appear to be involved in dehydration catalysis. The three-dimensional positions of these residues match those of corresponding histidines at the active center of human PCD. Based on the coincidence of catalytic parameters, and on the similar effects induced by the mutations, it is concluded that the substrate binding mode and the reaction mechanisms of bacterial and human PCD are basically identical.
authors.affiliation: Department of Biology, University of Konstanz, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Köster
authors.forename: G
authors.initials: G
authors.lastname: Stier
authors.forename: N
authors.initials: N
authors.lastname: Kubasch
authors.forename: H C
authors.initials: HC
authors.lastname: Curtius
authors.forename: S
authors.initials: S
authors.lastname: Ghisla
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D006801:Humans; D006836:Hydro-Lyases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid
chemical_list: D006836:Hydro-Lyases; C076392:pterin-4a-carbinolamine dehydratase