Figure 4.

The Combined SIV_mnd-2 Vpx/DCAF1-CtD/SAMHD1_mnd-NtD Ternary Interface

(A) Interface of DCAF1-CtD and SAMHD1_mnd NLS region. β strands from WD40 repeat-1 and -2 of DCAF1-CtD are shown in gray cartoon representation. The N-terminal NLS region of SAMHD1_mnd is shown in magenta. Residues making contacts at the interface are shown in stick representation with hydrogen bonding and salt bridge interactions displayed as dashed lines.

(B) The Vpx-SAMHD1_mnd NLS region interface. The ternary complex is displayed (central) in the same orientation and representation as Figure 2. Details of SAMHD1-Vpx interactions within the boxed region are shown left and right. Residues in SAMHD1 (magenta) and Vpx (blue) making contacts at the interface are shown in stick representation with hydrogen bonding and salt bridge interactions displayed as dashed lines.

(C) Quantification of reporter expression in stable cell lines containing degron constructs with the indicated N-terminal truncations of SAMHD1_mnd. Cells were transduced with increasing titers of particles expressing SIV_mnd-2 Vpx together with YFP and degron reporter expression (EGFP) measured by flow cytometry.