title: Structures of the N47A and E109Q mutant proteins of pyruvoyl-dependent arginine decarboxylase from Methanococcus jannaschii.
abstract: Pyruvoyl-dependent arginine decarboxylase (PvlArgDC) catalyzes the first step of the polyamine-biosynthetic pathway in plants and some archaebacteria. The pyruvoyl group of PvlArgDC is generated by an internal autoserinolysis reaction at an absolutely conserved serine residue in the proenzyme, resulting in two polypeptide chains. Based on the native structure of PvlArgDC from Methanococcus jannaschii, the conserved residues Asn47 and Glu109 were proposed to be involved in the decarboxylation and autoprocessing reactions. N47A and E109Q mutant proteins were prepared and the three-dimensional structure of each protein was determined at 2.0 A resolution. The N47A and E109Q mutant proteins showed reduced decarboxylation activity compared with the wild-type PvlArgDC. These residues may also be important for the autoprocessing reaction, which utilizes a mechanism similar to that of the decarboxylation reaction.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850-1301, USA.
authors.forename: Erika V
authors.initials: EV
authors.lastname: Soriano
authors.forename: Diane E
authors.initials: DE
authors.lastname: McCloskey
authors.forename: Cynthia
authors.initials: C
authors.lastname: Kinsland
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Pegg
authors.forename: Steven E
authors.initials: SE
authors.lastname: Ealick
mesh_terms: D001665:Binding Sites; D002262:Carboxy-Lyases / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D003001:Cloning, Molecular; D003460:Crystallization; D017017:Methanococcus / Q000201:enzymology* / Q000235:genetics*; D008958:Models, Molecular; D008968:Molecular Conformation; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D011773:Pyruvates / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D011773:Pyruvates; D002262:Carboxy-Lyases; C019722:arginine decarboxylase