title: A molecular switch and electronic circuit modulate catalase activity in catalase-peroxidases.
abstract: The catalase reaction of catalase-peroxidases involves catalase-specific features built into a peroxidase core. An arginine, 20 A from the active-site heme, acts as a molecular switch moving between two conformations, one that activates heme oxidation and one that activates oxoferryl heme reduction by H(2)O(2), facilitating the catalatic pathway in a peroxidase. The influence of the arginine is imparted to the heme through its association with or dissociation from a tyrosinate that modulates reactivity through a Met-Tyr-Trp crosslinked adduct and a pi electron interaction of the heme with the adduct Trp.
authors.affiliation: Department of Microbiology, University of Manitoba, Winnipeg MB R3T 2N2, Canada.
authors.forename: Xavier
authors.initials: X
authors.lastname: Carpena
authors.forename: Ben
authors.initials: B
authors.lastname: Wiseman
authors.forename: Taweewat
authors.initials: T
authors.lastname: Deemagarn
authors.forename: Rahul
authors.initials: R
authors.lastname: Singh
authors.forename: Jacek
authors.initials: J
authors.lastname: Switala
authors.forename: Anabella
authors.initials: A
authors.lastname: Ivancich
authors.forename: Ignacio
authors.initials: I
authors.lastname: Fita
authors.forename: Peter C
authors.initials: PC
authors.lastname: Loewen
mesh_terms: D001120:Arginine / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D016957:Burkholderia pseudomallei / Q000201:enzymology; D002374:Catalase / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004581:Electronics; D006418:Heme / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D014867:Water / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D014867:Water; D006418:Heme; D001120:Arginine; D006861:Hydrogen Peroxide; D010544:Peroxidases; D002374:Catalase