Ubiquitin associated protein domain

Ubiquitin-associated domains contain approximately 40 residues and bind ubiquitin noncovalently. It is thought to be encoded for by STS-1 gene in humans.

Structure
They adopt a secondary structure consisting of three alpha-helice which are connected by loops.

Function
They have been identified in modular proteins involved in protein trafficking, DNA repair, proteasomal degradation, and cell cycle regulation. UBA bind to ubiquitin and aids all the cellular processes involved with ubiquitin; this includes:
 * Antigen processing
 * Apoptosis
 * Biogenesis of organelles
 * Cell cycle and division
 * DNA transcription and DNA repair
 * Differentiation and development
 * Immune response and inflammation
 * Neural and muscular degeneration
 * Morphogenesis of neural networks
 * Modulation of cell surface receptors, ion channels and the secretory pathway
 * Response to stress and extracellular modulators
 * Ribosome biogenesis
 * Viral infection