ID 2.8.1.2 DE 3-mercaptopyruvate sulfurtransferase. CA 2-oxo-3-sulfanylpropanoate + [thioredoxin]-dithiol = [thioredoxin]- CA disulfide + H(+) + hydrogen sulfide + pyruvate. CC -!- The enzyme catalyzes a transsulfuration reaction from CC 3-mercaptopyruvate to an internal cysteine residue. CC -!- In the presence of a dithiol such as reduced thioredoxin or CC dihydrolipoate, the sulfanyl sulfur is released as hydrogen sulfide. CC -!- The enzyme participates in a sulfur relay process that leads to the CC 2-thiolation of some tRNAs and to protein urmylation by transferring CC sulfur between the NFS1 cysteine desulfurase (EC 2.8.1.7) and the CC MOCS3 sulfurtransferase (EC 2.8.1.11). DR O64530, STR1_ARATH ; Q24JL3, STR2_ARATH ; P58388, THTM_ECO57 ; DR P31142, THTM_ECOLI ; P25325, THTM_HUMAN ; Q99J99, THTM_MOUSE ; DR Q9I452, THTM_PSEAE ; P97532, THTM_RAT ; Q9USJ1, THTM_SCHPO ; //