Biochemical inhibition of the proteasome, or specific mutations to the RING domain uncouple the block to reverse transcription from inhibition of infection, demonstrating that TRIM5α can also inhibit steps after reverse transcription [13,14].The TRIM protein family is characterized by the presence of the tripartite RBCC motif, consisting of a RING domain, one or more B-box domains, and a coiled-coil domain. This evidence concerns the gene TRAT1 and infection.