title: Atomic resolution crystal structure of hydroxynitrile lyase from Hevea brasiliensis.
abstract: The X-ray crystal structure of native hydroxynitrile lyase from Hevea brasiliensis (Hb-HNL) has been determined at 1.1 A resolution. It refined to a final R of 11.5% for all data and an Rfree of 14.4%. The favorable data-to-parameter ratio at atomic resolution made the refinement of individual anisotropic displacement parameters possible. The data also allowed a clear distinction of the alternate orientations of all histidine and the majority of asparagine and glutamine side chains. A number of hydrogen atoms, including one on the imidazole of the mechanistically important His-235, became visible as peaks in a difference electron density map. The structure revealed a discretely disordered sidechain of Ser-80, which is part of the putative catalytic triad. Analysis of the anisotropy indicated an increased mobility of residues near the entrance to the active site and within the active site.
authors.affiliation: Abteilung für Strukturbiologie, Institut für Physikalische Chemie, Universität Graz, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Gruber
authors.forename: M
authors.initials: M
authors.lastname: Gugganig
authors.forename: U G
authors.initials: UG
authors.lastname: Wagner
authors.forename: C
authors.initials: C
authors.lastname: Kratky
mesh_terms: D000446:Aldehyde-Lyases / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019665:Euphorbiaceae / Q000201:enzymology*; D006859:Hydrogen / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation
chemical_list: D006859:Hydrogen; D000446:Aldehyde-Lyases; C079359:hydroxymandelonitrile lyase