RING finger, HC subclass, found in promyelocytic leukemia protein (PML) and similar proteins
Protein PML, also known as RING finger protein 71 (RNF71) or tripartite motif-containing protein 19 (TRIM19), is predominantly a nuclear protein with a broad intrinsic antiviral activity. It is the eponymous component of PML nuclear bodies (PML NBs) and has been implicated in a wide variety of cell processes, including DNA damage signaling, apoptosis, and transcription. PML interferes with the replication of many unrelated viruses, including human immunodeficiency virus 1 (HIV-1), human foamy virus (HFV), poliovirus, influenza virus, rabies virus, EMCV, adeno-associated virus (AAV), and vesicular stomatitis virus (VSV). It also selectively interacts with misfolded proteins through distinct substrate recognition sites and conjugates these proteins with the small ubiquitin-like modifiers (SUMOs) through its SUMO ligase activity. PML belongs to the C-V subclass of TRIM (tripartite motif) family of proteins that are defined by an N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a C3HC4-type RING-HC finger, Bbox1 and Bbox2, and a coiled coil region, as well as an uncharacterized region positioned C-terminal to the RBCC domain.