Plays a role in L-cysteine detoxification; it has been speculated to be a cysteine desulfhydrase (PubMed:27435271). Transcription induced by L-cysteine (in vivo), under control of DecR. Member of the dlsT(yhaO)-yhaM operon. Slightly increased sensitivity to excess L-cysteine, the effect is more pronounced in M9 minimal medium. Cells produce about 9% of wild-type levels of hydrogen sulfide in the presence of excess cysteine. Belongs to the UPF0597 family.