Cystathionine beta-synthase (CBS)

Hydro-lyase catalyzing the initial step of the transsulfuration pathway, where the hydroxyl group of L-serine is displaced by L-homocysteine at a beta-replacement response to form L-cystathionine, the precursor of L-cysteine. This catabolic route allows the elimination of L-methionine as well as the toxic metabolite L- homocysteine (PubMed:23981774, PubMed:20506325, PubMed:23974653).

Also involved in the production of hydrogen sulfide, a gasotransmitter with signaling and cytoprotective effects on neurons (By similarity). .