title: A novel inhibitor-binding site on the HIV-1 capsid N-terminal domain leads to improved crystallization via compound-mediated dimerization.
abstract: Despite truly impressive achievements in the global battle against HIV there remains a need for new drugs directed against novel targets, and the viral capsid protein (CA) may represent one such target. Intense structural characterization of CA over the last two decades has provided unprecedented insight into the structure and assembly of this key viral protein. Furthermore, several inhibitor-binding sites that elicit antiviral activity have been reported on CA, two of which are located on its N-terminal domain (CANTD). In this work, the binding of a novel capsid-assembly inhibitor that targets a unique inhibitory site on CANTD is reported. Moreover, whereas cocrystallization of CANTD in complex with ligands has proven to be challenging in the past, the use of this inhibitor as a tool compound is shown to vastly facilitate ternary cocrystallizations with CANTD. This improvement in crystallization is likely to be achieved through the formation of a compound-mediated homodimer, the intrinsic symmetry of which greatly increases the prospect of generating a crystal lattice. While protein engineering has been used in the literature to support a link between the inherent symmetry of a macromolecule and its propensity to crystallize, to our knowledge this work represents the first use of a synthetic ligand for this purpose.
authors.affiliation: Department of Chemistry, Boehringer Ingelheim (Canada) Ltd, 2100 Cunard Street, Laval, Quebec H7S 2G5, Canada. RESGeneral.LAV@boehringer-ingelheim.com
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Lemke
authors.forename: Steve
authors.initials: S
authors.lastname: Titolo
authors.forename: Nathalie
authors.initials: N
authors.lastname: Goudreau
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Faucher
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Mason
authors.forename: Pierre
authors.initials: P
authors.lastname: Bonneau
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002213:Capsid / Q000737:chemistry* / Q000378:metabolism; D036022:Capsid Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D015497:HIV-1 / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D014961:X-Ray Diffraction
chemical_list: D000998:Antiviral Agents; D036022:Capsid Proteins
keywords: HIV-1; capsid-assembly inhibitor; cocrystallization; dimerization