Able to cleave dimethylsulfonioproprionate (DMSP), releasing dimethyl sulfide (DMS). DMS is the principal form by which sulfur is transported from oceans to the atmosphere. The real activity of the protein is however subject to debate and it is unclear whether it constitutes a real dimethylsulfonioproprionate lyase in vivo: the low activity with DMSP as substrate suggests that DMSP is not its native substrate. S,S-dimethyl-beta-propiothetin = acrylate + dimethyl sulfide + H(+) Binds 2 divalent metal cation ions per subunit. Fe(2+), which is the most abundant metal ion found in the X-ray structure, may constitute the physiological cofactor. Homodimer. Belongs to the peptidase M24B family.