UBX
solution structure of the ubx domain of kiaa0794 protein
Identifiers
Symbol	UBX
Pfam	PF00789
Pfam clan	CL0072
InterPro	IPR001012
SMART	UBX
SCOP2	1i42 / SCOPe / SUPFAM
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

In molecular biology, the UBX protein domain is found in ubiquitin-regulatory proteins, which are members of the ubiquitination pathway, as well as a number of other ubiquitin-like proteins including FAF-1 (FAS-associated factor 1), the human Rep-8 reproduction protein and several hypothetical proteins from yeast. The function of the UBX domain is not known although the fragment of avian FAF-1 containing the UBX domain causes apoptosis of transfected cells.

Function

So far, as yet, no general function for the UBX domain has yet emerged.^[1] Additionally, the absence of a carboxy-terminal di-glycine motif, however, indicates that UBX domains are not covalently attached to target proteins in a ubiquitin-like manner.^[2]

Structure

The UBX domain comprises about 80 amino acid residues. They are distinct structural units defining a large family of proteins that often exhibit a modular domain architecture three-dimensional structures of UBX domains reveal a close structural relationship with ubiquitin despite the lack of significant sequence homology^[2]

Homology

UBX domain is very similar to ubiquitin which gives us some indication of evolution. There are ubiquitin fusion which seem to be advantageous for ribosomal subunit folding.^[2]

References