2.8.1.4	ATP	-	
2.8.1.4	ATP	absolute requirement, other nucleotides are inactive	
2.8.1.4	additional information	beta-mercaptopyruvate is inactive either as a cofactor or as a sulfur donor	
2.8.1.4	additional information	sulfur transfer obtained with ADP is apparently due to the formation of ATP by the reaction 2 ADP = ATP + AMP, AMP is totally inactive as activating nucleotide	
2.8.1.4	additional information	the enzyme requires two conserved Cys residues (Cys265 and Cys268), which are arranged in a CXXC motif in the PP-loop domain, for both in vitro and in vivo activities to generate 4-thiouridine in tRNAs	
2.8.1.4	pyridoxal 5'-phosphate	-