6.2.1.45	ATP + ubiquitin + SUMO2	UBE1DC1 greatly activates SUMO2 in the nucleus or transfers activated-SUMO2 to nucleus after conjugation of SUMO2 in the cytoplasm	?	-	?	400478	
6.2.1.45	ATP + ubiquitin + ubiquitin-fold modifier 1	-	?	-	?	400498	
6.2.1.45	ATP + ubiquitin + Ufm1	-	?	-	?	400499	
6.2.1.45	additional information	UBE1L2 transfers activated ubiquitin onto UbcH5b and supports E3-mediated polyubiquitylation	?	-	?	89	
6.2.1.45	additional information	impaired nucleotide excision repair upon macrophage differentiation is corrected by E1 ubiquitin-activating enzyme	?	-	?	89	
6.2.1.45	additional information	a lysine 48-linked polyubiquitin chain, assembled upon an internal lysine residue of a substrate protein, becomes the principle signal for recognition and target degradation by the 26S proteasome. E1 is not only essential for the initial ATP-dependent activation of ubiquitin in the ubiquitin degradtion pathway, but also capable of the catalytic extension of the polyubiquitin chain on a mono-ubiquitinated substrate	?	-	?	89	
6.2.1.45	additional information	E1 consumes ATP and converts ubiquitin to a transfer-competent, enzyme-bound thioester. The reaction begins with ubiquitin-adenylate formation and the release of diphosohate. The active site cysteine of the E1 then displaces the AMP leading to a ubiquitin-E1 thioester complex	?	-	?	89	
6.2.1.45	additional information	the thioester formation assay is performed using recombinant proteins expressed in Escherichia coli. The activation of ubiquitin by purified UBE1 is identified in vitro by SDS-PAGE	?	-	?	89	
6.2.1.45	additional information	E1 activity is assesssed by the capacity of the enzyme to form a thiol ester conjugate with ubiquitin in an ATP-dependent process and to transfer this activated ubiquitin molecule to an conjugating enzyme	?	-	?	89	
6.2.1.45	additional information	residue Cys194 lies within a region of identity to active-site Cys88 of the ubiquitin carrier protein E2, suggesting a potential role for this region in enzymatic function. Residue Cys454 lies within a region of identity to the thiol ester consensus sequence of several proteins involved in thioester formation	?	-	?	89