title: Crystal structure of trichosanthin-NADPH complex at 1.7 A resolution reveals active-site architecture.
abstract: We describe here the crystal structure of the trichosanthin-NADPH complex determined at a resolution of 1.7 A. The adenine base stacks between Tyr 70 and Tyr 111. Arg 163, Glu 160 and Tyr 70 form hydrogen bonds to N(3), O(3') and, through a water molecule, to N(9) of adenosine, respectively. This is the first high resolution structure of a complex between a ribosome-inactivating protein and a substrate analogue, in which the electron density of the N-glycosidic bond is well defined and the preassociated water, thought to be responsible for hydrolyzing the N-C bond, is also explicitly elucidated.
authors.affiliation: Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.
authors.forename: J P
authors.initials: JP
authors.lastname: Xiong
authors.forename: Z X
authors.initials: ZX
authors.lastname: Xia
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001665:Binding Sites; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D006868:Hydrolysis; D015394:Molecular Structure; D009249:NADP / Q000737:chemistry* / Q000494:pharmacology; D015978:Trichosanthin / Q000037:antagonists & inhibitors / Q000737:chemistry*
chemical_list: D009249:NADP; D015978:Trichosanthin