title: Crystal structures of the inactive D30N mutant of feline immunodeficiency virus protease complexed with a substrate and an inhibitor.
abstract: Crystal structures of complexes of a D30N mutant of feline immunodeficiency virus protease (FIV PR) complexed with a statine-based inhibitor (LP-149), as well as with a substrate based on a modification of this inhibitor (LP-149S), have been solved and refined at resolutions of 2.0 and 1.85 A, respectively. Both the inhibitor and the substrate are bound in the active site of the mutant protease in a similar mode, which also resembles the mode of binding of LP-149 to the native protease. The carbonyl oxygen of the scissile bond in the substrate is not hydrated and is located within the distance of a hydrogen bond to an amido nitrogen atom from one of the two asparagines in the active site of the enzyme. The nitrogen atom of the scissile bond is 3.25 A from the conserved water molecule (Wat301). A model of a tetrahedral intermediate bound to the active site of the native enzyme was built by considering the interactions observed in all three crystal structures of FIV PR. Molecular dynamics simulations of this model bound to native wild-type FIV PR were carried out, to investigate the final stages of the catalytic mechanism of aspartic proteases.
authors.affiliation: Macromolecular Structure Laboratory, NCI-Frederick Cancer Research and Development Center, Frederick, Maryland 21702, USA.
authors.forename: G S
authors.initials: GS
authors.lastname: Laco
authors.forename: C
authors.initials: C
authors.lastname: Schalk-Hihi
authors.forename: J
authors.initials: J
authors.lastname: Lubkowski
authors.forename: G
authors.initials: G
authors.lastname: Morris
authors.forename: A
authors.initials: A
authors.lastname: Zdanov
authors.forename: A
authors.initials: A
authors.lastname: Olson
authors.forename: J H
authors.initials: JH
authors.lastname: Elder
authors.forename: A
authors.initials: A
authors.lastname: Wlodawer
authors.forename: A
authors.initials: A
authors.lastname: Gustchina
mesh_terms: D001216:Asparagine / Q000235:genetics; D001224:Aspartic Acid / Q000235:genetics; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics*; D001665:Binding Sites / Q000235:genetics; D018360:Crystallography, X-Ray; D004789:Enzyme Activation / Q000235:genetics; D016089:Immunodeficiency Virus, Feline / Q000201:enzymology* / Q000235:genetics; D046911:Macromolecular Substances; D016297:Mutagenesis, Site-Directed; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011480:Protease Inhibitors / Q000737:chemistry* / Q000378:metabolism; D012996:Solutions; D013379:Substrate Specificity / Q000235:genetics
chemical_list: C095554:LP 149; D046911:Macromolecular Substances; D009842:Oligopeptides; D010455:Peptides; D011480:Protease Inhibitors; D012996:Solutions; D001224:Aspartic Acid; D001216:Asparagine; D016282:Aspartic Acid Endopeptidases; C095555:FIV protease