FIG. 4.
Effects of the TRIM21 RING and B-box 2 domains on the antiretroviral activity of TRIM5αrh. (A) Structures of the chimeric proteins involving the TRIM21 RING and B-box 2 domains. The RING domain, the B-box 2 domain, and the RING domain plus the L1 linker region of TRIM5αrh were individually replaced with the corresponding region from human TRIM21 (shaded black). (B) Expression of the TRIM21-TRIM5αrh chimeras. HeLa lysates were analyzed by Western blotting as described in the legend to Fig. 2. (C and D) Antiretroviral activities of TRIM21-TRIM5αrh chimeras. HeLa cells expressing the chimeric proteins were incubated with HIV-1-GFP (C) and N-MLV-GFP (D) and then analyzed for GFP expression by FACS.