UBA domain found in Saccharomyces cerevisiae DNA-damage response protein Ddi1 and similar proteins
Ddi1, also called v-SNARE-master 1 (Vsm1), is a ubiquitin receptor involved in regulation of the cell cycle and late secretory pathway in Saccharomyces cerevisiae. It functions as a ubiquitin association domain (UBA)- ubiquitin-like-domain (UBL) shuttle protein that is required for the proteasome to enable ubiquitin-dependent degradation of its ligands. For instance, Ddi1 plays an essential role in the final stages of proteasomal degradation of Ho endonuclease and of its cognate FBP, Ufo1. Moreover, Ddi1 and its associated protein Rad23p play a cooperative role as negative regulators in yeast PHO pathway. Ddi1 contains an N-terminal UBL domain and a C-terminal UBA domain. It also harbors a central retroviral aspartyl-protease-like domain (RVP) which may be important in cell-cycle control. At this point, Ddi1 may function proteolytically during regulated protein turnover in the cell. This family also includes mammalian regulatory solute carrier protein family 1 member 1 (RSC1A1), also called transporter regulator RS1 (RS1) which mediates transcriptional and post-transcriptional regulation of Na(+)-D-glucose cotransporter SGLT1.
Jiyao W et al.(2023). "The conserved domain database in 2023.",