title: A symmetric region of the HIV-1 integrase dimerization interface is essential for viral replication.
abstract: HIV-1 integrase (IN) is an important target for contemporary antiretroviral drug design research. Historically, efforts at inactivating the enzyme have focused upon blocking its active site. However, it has become apparent that new classes of allosteric inhibitors will be necessary to advance the antiretroviral field in light of the emergence of viral strains resistant to contemporary clinically used IN drugs. In this study we have characterized the importance of a close network of IN residues, distant from the active site, as important for the obligatory multimerization of the enzyme and viral replication as a whole. Specifically, we have determined that the configuration of six residues within a highly symmetrical region at the IN dimerization interface, composed of a four-tiered aromatic interaction flanked by two salt bridges, significantly contributes to proper HIV-1 replication. Additionally, we have utilized a quantitative luminescence assay to examine IN oligomerization and have determined that there is a very low tolerance for amino acid substitutions along this region. Even conservative residue substitutions negatively impacted IN multimerization, resulting in an inactive viral enzyme and a non-replicative virus. We have shown that there is a very low tolerance for amino acid variation at the symmetrical dimeric interface region characterized in this study, and therefore drugs designed to target the amino acid network detailed here could be expected to yield a significantly reduced number of drug-resistant escape mutations compared to contemporary clinically-evaluated antiretrovirals.
authors.affiliation: Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA.
authors.forename: Erik
authors.initials: E
authors.lastname: Serrao
authors.forename: Wannes
authors.initials: W
authors.lastname: Thys
authors.forename: Jonas
authors.initials: J
authors.lastname: Demeulemeester
authors.forename: Laith Q
authors.initials: LQ
authors.lastname: Al-Mawsawi
authors.forename: Frauke
authors.initials: F
authors.lastname: Christ
authors.forename: Zeger
authors.initials: Z
authors.lastname: Debyser
authors.forename: Nouri
authors.initials: N
authors.lastname: Neamati
mesh_terms: D000494:Allosteric Regulation; D000495:Allosteric Site; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D004926:Escherichia coli / Q000235:genetics; D019427:HIV Integrase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000502:physiology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
chemical_list: D011994:Recombinant Proteins; D019427:HIV Integrase; C514801:p31 integrase protein, Human immunodeficiency virus 1