Structural and mechanistic bases for a potent HIV-1 capsid inhibitor
S.M. Bester, Guochao Wei, Haiyan Zhao, Daniel Adu‐Ampratwum, Naseer Iqbal, Valentine V. Courouble, Ashwanth C. Francis, Arun S. Annamalai, Parmit K. Singh, Nikoloz Shkriabai, Peter Van Blerkom, James H. Morrison, Eric M. Poeschla, Alan Engelman, Gregory B. Melikyan, Patrick R. Griffin, James R. Fuchs, Francisco J. Asturias, Mamuka Kvaratskhelia
Abstract
The potent HIV-1 capsid inhibitor GS-6207 is an investigational principal component of long-acting antiretroviral therapy. We found that GS-6207 inhibits HIV-1 by stabilizing and thereby preventing functional disassembly of the capsid shell in infected cells. X-ray crystallography, cryo-electron microscopy, and hydrogen-deuterium exchange experiments revealed that GS-6207 tightly binds two adjoining capsid subunits and promotes distal intra- and inter-hexamer interactions that stabilize the curved capsid lattice. In addition, GS-6207 interferes with capsid binding to the cellular HIV-1 cofactors Nup153 and CPSF6 that mediate viral nuclear import and direct integration into gene-rich regions of chromatin. These findings elucidate structural insights into the multimodal, potent antiviral activity of GS-6207 and provide a means for rationally developing second-generation therapies.