In enzymology, a mycothione reductase () is an enzyme that catalyzes the chemical reaction mycothione + NAD(P)H + H + 2 mycothiol + NADP+ in M. tuberculosis and other actinomycetes. The 2 substrates of this enzyme are mycothiol and NADPH, whereas 2 molecules of mycothione and NADP+ are formed as products. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is mycothiol:NAD(P)+ oxidoreductase. This enzyme is also called mycothiol-disulfide reductase. References EC 1.8.1 NADPH-dependent enzymes NADH-dependent enzymes Enzymes of unknown structure