National Center for
4LQW: Crystal Structure Of Hiv-1 Capsid N-terminal Domain In Complex With Nup358 Cyclophilin
Retrovirology (2013) 10 p.81
BACKGROUND: Lentiviruses such as HIV-1 can be distinguished from other retroviruses by the cyclophilin A-binding loop in their capsid and their ability to infect non-dividing cells. Infection of non-dividing cells requires transport through the nuclear pore but how this is mediated is unknown. RESULTS: Here we present the crystal structure of the N-terminal capsid domain of HIV-1 in complex with the cyclophilin domain of nuclear pore protein NUP358. The structure reveals that HIV-1 is positioned to allow single-bond resonance stabilisation of exposed capsid residue P90. NMR exchange experiments demonstrate that NUP358 is an active isomerase, which efficiently catalyzes cis-trans isomerization of the HIV-1 capsid. In contrast, the distantly related feline lentivirus FIV can bind NUP358 but is neither isomerized by it nor requires it for infection. CONCLUSION: Isomerization by NUP358 may be preserved by HIV-1 to target the nuclear pore and synchronize nuclear entry with capsid uncoating.