TRIM5 is a member of a broad family of otherwise unrelated proteins defined by the presence of a tripartite motif containing a RING domain, a B-box type 1, and a B-box type 2, followed by a coiled-coil region. TRIM5 has five alternately spliced isoforms, the longest of which is the alpha variant which also contains a carboxy-terminal B30.2 (SPRY) domain. While a function has not yet been assigned to TRIM5-gamma, it is known that expression of TRIM5-a variants from humans, rhesus monkeys, and African green monkeys enable resistance to infection by various retroviruses including HIV-1, albeit at differing efficiencies. Furthermore, the TRIM5δ isoform appears to serve as a scaffold for the assembly of endogenous BTBD1 and BTBD2 proteins and also exhibits autoubiquitination activity in a RING finger- and UbcH5B-dependent manner.
RING finger protein 88; RING-type E3 ubiquitin transferase TRIM5; tripartite motif containing 5 transcript variant iota; tripartite motif containing 5 transcript variant kappa; tripartite motif protein TRIM5; Tripartite motif-containing protein 5