Betaine reductase is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are acetyl phosphate, trimethylamine, and thioredoxin disulfide, whereas its 3 products are N,N,N-trimethylglycine, phosphate, and thioredoxin. This enzyme belongs to the family of oxidoreductases, specifically those acting on X-H and Y-H to form an X-Y bond with a disulfide as acceptor. The systematic name of this enzyme class is acetyl-phosphate trimethylamine:thioredoxin disulfide oxidoreductase (N,N,N-trimethylglycine-forming).