Figure 1.

Interactions of N-terminal Vpr with CypA. Schematic overview of the N-terminal sequence of HIV-1_NL4-3 Vpr showing its interactions with CypA that include regions undergoing transient enzymatic prolyl cis/trans catalysis and the region of strong selective binding. In aqueous phosphate buffer at pH 7 N-terminal Vpr peptides, as well as full-length Vpr, are essentially unstructured but assume α-helical structure at lower pH and under hydrophobic conditions [7,19]. Notice that the region of selective strong binding of Vpr with CypA includes the entire loop region connecting regions that form α-helices 1 and 2.