title: The crystal structure of a novel SAM-dependent methyltransferase PH1915 from Pyrococcus horikoshii.
abstract: The S-adenosyl-L-methionine (SAM)-dependent methyltransferases represent a diverse and biologically important class of enzymes. These enzymes utilize the ubiquitous methyl donor SAM as a cofactor to methylate proteins, small molecules, lipids, and nucleic acids. Here we present the crystal structure of PH1915 from Pyrococcus horikoshii OT3, a predicted SAM-dependent methyltransferase. This protein belongs to the Cluster of Orthologous Group 1092, and the presented crystal structure is the first representative structure of this protein family. Based on sequence and 3D structure analysis, we have made valuable functional insights that will facilitate further studies for characterizing this group of proteins. Specifically, we propose that PH1915 and its orthologs are rRNA- or tRNA-specific methyltransferases.
authors.affiliation: Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada.
authors.forename: Warren
authors.initials: W
authors.lastname: Sun
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xu
authors.forename: Marina
authors.initials: M
authors.lastname: Pavlova
authors.forename: Aled M
authors.initials: AM
authors.lastname: Edwards
authors.forename: Andrzej
authors.initials: A
authors.lastname: Joachimiak
authors.forename: Alexei
authors.initials: A
authors.lastname: Savchenko
authors.forename: Dinesh
authors.initials: D
authors.lastname: Christendat
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D008780:Methyltransferases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D043902:Pyrococcus horikoshii / Q000201:enzymology*; D012436:S-Adenosylmethionine / Q000378:metabolism*
chemical_list: D021122:Protein Subunits; D012436:S-Adenosylmethionine; D008780:Methyltransferases