title: Crystal structure of a squalene cyclase in complex with the potential anticholesteremic drug Ro48-8071.
abstract: Squalene-hopene cyclase (SHC) catalyzes the conversion of squalene into pentacyclic compounds. It is the prokaryotic counterpart of the eukaryotic oxidosqualene cyclase (OSC) that catalyzes the steroid scaffold formation. Because of clear sequence homology, SHC can serve as a model for OSC, which is an attractive target for anticholesteremic drugs. We have established the crystal structure of SHC complexed with Ro48-8071, a potent inhibitor of OSC and therefore of cholesterol biosynthesis. Ro48-8071 is bound in the active-center cavity of SHC and extends into the channel that connects the cavity with the membrane. The binding site of Ro48-8071 is largely identical with the expected site of squalene; it differs from a previous model based on photoaffinity labeling. The knowledge of the inhibitor binding mode in SHC is likely to help develop more potent inhibitors for OSC.
authors.affiliation: Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, D-79104-, Freiburg im Breisgau, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lenhart
authors.forename: Wilhelm A
authors.initials: WA
authors.lastname: Weihofen
authors.forename: Axel E W
authors.initials: AE
authors.lastname: Pleschke
authors.forename: Georg E
authors.initials: GE
authors.lastname: Schulz
mesh_terms: D000924:Anticholesteremic Agents / Q000737:chemistry* / Q000378:metabolism*; D001406:Bacillaceae / Q000201:enzymology; D001577:Benzophenones / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D019751:Intramolecular Transferases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism; D008958:Models, Molecular; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D000924:Anticholesteremic Agents; D001577:Benzophenones; D008565:Membrane Proteins; D011994:Recombinant Proteins; C105726:Ro 48-8071; D019751:Intramolecular Transferases; C066630:squalene-hopene cyclase