B-box-type 2 zinc finger found in tripartite motif-containing protein 46 (TRIM46) and similar proteins
TRIM46, also known as gene Y protein (GeneY) or tripartite, fibronectin type-III and C-terminal SPRY motif protein (TRIFIC), is a microtubule-associated protein that specifically localizes to the proximal axon, partly overlaps with the axon initial segment (AIS) at later stages, and organizes uniform microtubule orientation in axons. It controls neuronal polarity and axon specification by driving the formation of parallel microtubule arrays. TRIM46 belongs to the C-I subclass of TRIM (tripartite motif) family of proteins, which are defined by their N-terminal RBCC (RING, Bbox, and coiled coil) domains, including three consecutive zinc-binding domains, a RING finger, Bbox1 and Bbox2, and a coiled coil region, as well as a COS (carboxyl-terminal subgroup one signature) box, a fibronectin type III (FN3) domain, and a B30.2/SPRY (SplA and ryanodine receptor) domain positioned C-terminal to the RBCC domain. The type 2 B-box (Bbox2) zinc finger is characterized by a CHC3H2 zinc-binding consensus motif.