Download MendeleyMolecular Determinants for Recognition of Divergent Samhd1 Proteins by the Lentiviral Accessory Protein Vpx.
Schwefel, D., Boucherit, V.C., Christodoulou, E., Walker, P.A., Stoye, J.P., Bishop, K.N., Taylor, I.A.(2015) Cell Host Microbe 17: 489
- PubMed: 25856754
- DOI: https://doi.org/10.1016/j.chom.2015.03.004
- Primary Citation of Related Structures:
5AJA - PubMed Abstract:
The SAMHD1 triphosphohydrolase inhibits HIV-1 infection of myeloid and resting T cells by depleting dNTPs. To overcome SAMHD1, HIV-2 and some SIVs encode either of two lineages of the accessory protein Vpx that bind the SAMHD1 N or C terminus and redirect the host cullin-4 ubiquitin ligase to target SAMHD1 for proteasomal degradation. We present the ternary complex of Vpx from SIV that infects mandrills (SIVmnd-2) with the cullin-4 substrate receptor, DCAF1, and N-terminal and SAM domains from mandrill SAMHD1. The structure reveals details of Vpx lineage-specific targeting of SAMHD1 N-terminal "degron" sequences. Comparison with Vpx from SIV that infects sooty mangabeys (SIVsmm) complexed with SAMHD1-DCAF1 identifies molecular determinants directing Vpx lineages to N- or C-terminal SAMHD1 sequences. Inspection of the Vpx-DCAF1 interface also reveals conservation of Vpx with the evolutionally related HIV-1/SIV accessory protein Vpr. These data suggest a unified model for how Vpx and Vpr exploit DCAF1 to promote viral replication.
Organizational Affiliation:
Division of Molecular Structure, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
