Cyclophilin A stabilizes the HIV-1 capsid through a novel non-canonical binding site
Cyclophilin A (CypA) is a host cell factor that is important in multiple pathways during an infection, including inflammation, immunity, and protein trafficking. Improper regulation of CypA plays a role in facilitating cancer, autoimmune disease, and HIV infections. Klaus Schulten, Peijun Zhang, and co-authors used a multidisciplinary approach to discover an interaction between CypA and the HIV-1 capsid protein. By resolving an 8-Å cryoEM structure and utilizing all-atom molecular dynamics and solid-state NMR, the authors unexpectedly reveal a novel capsid binding site on CypA. A single molecule of CypA is now known to bind two subunits of the HIV-1 capsid, resulting in increased capsid stabilization. Identification of this new binding site reveals the possibility for new HIV therapeutics that could target this unique interaction.
More information can be found in the complete Nature Communications article: http://www.nature.com/ncomms/2016/160304/ncomms10714/full/ncomms10714.html or in this recent news article: https://news.illinois.edu/blog/view/6367/335013#image-2