Structural Studies Of HIV Integrase

Mentor Areas

The Structural Biology of Retroviral Integrases. Retroviral integrase (IN) catalyzes the incorporation of viral cDNA into the host genome. The design of effective pharmacological treatments remains of paramount importance to the treatment of HIV/AIDS, and detailed structural models of intact IN oligomers in their various states are essential to new structure-based drug design efforts. My work on the retroviral integrase (IN) has focused on the understanding of higher-order structure and oligomeric forms of the full-length integrase when bound to host factors and DNA, with the overall goal of determining the molecular details of the larger macromolecular assemblies that underlie the steps of retroviral integration and other stages of the viral life cycle. My research has married X-ray crystallography and rigorous biophysical methods to approach these fundamental questions. These approaches have included the application of small angle X-ray and neutron scattering (SAXS/SANS), analytical ultracentrifugation, multi-angle light scattering, and molecular modeling. These studies have yielded understanding of the quaternary structure and stoichiometry of IN, IN-DNA, and IN-host factor assemblies. Most recently these approaches have been brought to bear on an exciting new class of allosteric inhibitors (“ALLINIs”) that is able to inhibit IN via selective modulation of its oligomeric properties. Surprisingly, ALLINIs interfere not with DNA integration but with viral particle assembly late during HIV replication. In 2016, we reported a breakthrough in the structural biology of HIV Integrase: the first crystal structure of HIV-1 Integrase in complex with the ALLINI GSK 1264. To our knowledge, this is the first time full-length HIV-1 integrase has been crystallized. The structure shows GSK1264 bound to the dimer interface of the catalytic domain, and also positioned at this interface is a C-terminal domain (CTD) from an adjacent IN dimer. In the crystal lattice, IN forms an open polymer mediated by this interaction. Further studies of a panel of ALLINIs show that HIV escape mutants with reduced sensitivity commonly alter amino acids at or near the inhibitor-mediated interface, and that HIV escape mutations often encode substitutions that reduce multimerization.

Description:

1. Structural studies of HIV Integrase-inhibitor complexes. Allosteric inhibitors of Integrase (ALLINIs) are an emerging class of HIV inhibitors that target the viral protein Integrase (IN).  X-ray crystallography will be used to understand the structural basis for the interaction of these molecules with their target.

2. Structural studies of protein-protein interactions between HIV IN and host factors and viral proteins.  HIV relies on a large network of host factors to drive the viral life cycle. The viral protein Integrase (IN) interacts with many host factors; these interactions are poorly understood on the atomic level. Biophysical tools including light scattering, analytical ultracentrifugation, and small-angle X-ray scattering will be used to understand the solution structure and stoichiometry of the putative complexes, alongside crystallization trials.

Preferred Qualifications

Prior Laboratory experience is not prerequisite, although welcome.  Students should be majoring in a related area (eg Biology, Chemistry, Biochemistry, Biophysics) with concurrent relevant coursework.  Attention to detail and time management skills are a must.