title: Closing of the flaps of HIV-1 protease induced by substrate binding: a model of a flap closing mechanism in retroviral aspartic proteases.
abstract: The active site of aspartic proteases is covered by one or more flaps, which control access to the active site and play a significant role in the binding of the substrate. An extensive conformational change of the flaps takes place upon binding of substrate to the active site. A long molecular dynamics simulation was performed on the complex consisting of a peptide (CA-p2) from a natural substrate cleavage site of the gag/pol polyprotein placed in the active site of HIV-1 protease (PR) with an open flap conformation. During the simulation, the substrate induced the closing of the flaps into the closed conformation in an asymmetrical way through a hydrophobic intermediate state cluster. The nature of the residues of HIV-1 PR identified to be important in the flap closing mechanism is conserved across known structures of retroviral aspartic proteases family. The flap closing mechanism described in HIV-1 PR is proposed to be a general model for flap closing in retroviral aspartic proteases.
authors.affiliation: Locus Pharmaceuticals, Four Valley Square, 512 Township Line Road, Blue Bell, Pennsylvania 19422, USA. gergely.toth@elan.com
authors.forename: Gergely
authors.initials: G
authors.lastname: Tóth
authors.forename: Attila
authors.initials: A
authors.lastname: Borics
mesh_terms: D016333:HIV Protease / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D011487:Protein Conformation; D013379:Substrate Specificity
chemical_list: D016333:HIV Protease