Figure 6.

Comparison to the SIV_smm Vpx/DCAF1-CtD/SAMHD1_hs-CtD Structure

(A) Superposition of the SIV_mnd-2 Vpx/DCAF1-CtD/SAMHD1_mnd-NtD and SIV_smm Vpx/DCAF1-CtD/SAMHD1_hs-CtD ternary complexes. Cartoons are colored as Figure 2 with the addition of SIV_smm Vpx (orange) and SAMHD1_hs-CtD (green). For clarity, only DCAF1-CtD from the mandrill complex is shown.

(B and C) Quantification of reporter expression in cells stably expressing the SAMHD1_mnd (1–114) degron reporter construct after transduction with increasing titers of particles expressing SIV_mnd-2 Vpx with mutations in (B) the N-terminal arm (V15W) and in (C) the di-tyrosine motif (Y62A/Y65A). The level of Vpx transduction (YFP) and degron reporter (EGFP) expression was measured by flow cytometry.

(D) Detailed view of the conserved VR2 Vpx di-tyrosine motif interaction with the DCAF1-CtD acidic loop and basic motifs of the SAMHD1_mnd-NtD (left) and SAMHD1_hs-CtD (right) degrons; see also Figure S5. Residues that contribute to the ternary interface are shown in stick representation with hydrogen bonding and salt bridge interactions displayed as dashed lines; see also Figure S6.