Sequence Note: HIV Type 2 Vif Proteins Have Specific Conserved Amino Acid Motifs

Functional Analysis of Vif Protein Shows Less Restriction of Human Immunodeficiency Virus Type 2 by APOBEC3G

“…As with HIV-1 Vif, the conserved cysteines (M6 and M7) in Vif2 are important for its function, indicating a structural conformational role of these residues due to a lack of expression when some of them are eliminated (M7). In addition, Vif2 specific conserved motifs are also essential for viral infectivity (39). The presence of these motifs in HIV-2 Vif protein may explain the different infectivity phenotype of this virus compared to HIV-1 in the absence of Vif.…”

“…In Fig. 2 is shown the comparison of Vif2 and Vif1 proteins where the conserved motifs are indicated (39). An identity of 25% was observed between these two proteins.…”

“…The HIV-2 vif gene has only 25% identity with vif from HIV-1 (39). Analysis of the HIV-2 Vif protein (Vif2) has been less extensive than studies with Vif1.…”

“…We performed mutational analyses of Vif2 with deletions and substitutions introduced into specific conserved motifs of the protein (39), as well as in conserved motifs between Vif1 and Vif2 (35). Mutant proteins were also characterized for their stability, expression, and cellular localization.…”

Structural perspectives on HIV‐1 Vif and APOBEC3 restriction factor interactions

“…9 Despite low sequence identity between HIV-1 and HIV-2 Vif proteins (<25%), both are encoded in similar genomic locations (between pol and env genes), have similar molar masses (23 kDa), and have similarly high pI values (~10). 10,11 As observed for HIV-1, Vif defects impaired HIV-2 infectivity. 12 These data collectively established Vif as a viral infectivity factor--hence its name.…”