Reaction catalyzed by tRNA 2-selenouridine synthase (2.9.1.3)

		+		5-methylaminomethyl-2-(S-geranyl)thiouridine34 in tRNA	=		5-methylaminomethyl-2-(Se-phospho)selenouridine34 in tRNA	+		(2E)-3,7-dimethylocta-2,6-diene-1-thiol
	selenophosphate	+		5-methylaminomethyl-2-(S-geranyl)thiouridine34 in tRNA	=		5-methylaminomethyl-2-(Se-phospho)selenouridine34 in tRNA	+		(2E)-3,7-dimethylocta-2,6-diene-1-thiol