Part of a sulfur-relay system required for 2-thiolation of 5-methylaminomethyl-2-thiouridine (mnm(5)s(2)U) at tRNA wobble positions. Could accept sulfur from TusD (By similarity). Interacts with the TusBCD complex. Interacts with MnmA (By similarity). Belongs to the DsrC/TusE family.