Cytoplasmic tRNA 2-thiolation protein 1 (CTU1)

Plays a central role in 2-thiolation of mcm(5)S(2)U in tRNA wobble positions of tRNA(Lys), tRNA(Glu) and tRNA(Gln). Directly binds tRNAs and probably acts by catalyzing adenylation of tRNAs, an intermediate required for 2-thiolation.

It's unclear whether it acts as a sulfurtransferase that transports sulfur from thiocarboxylated URM1 on the uridine of tRNAs at wobble position. .