Dimethylsulfoniopropionate (DMSP): From Biochemistry to Global Ecological Significance

Dimethylsulfoniopropionate (DMSP) is one of Earth's most abundant organosulfur compounds with important roles in stress tolerance, chemotaxis, global carbon and sulfur cycling, and climate-active gas production. Diverse marine prokaryotes and eukaryotes produce DMSP via three known pathways (methylation, transamination, and decarboxylation) and metabolize DMSP via three further pathways (demethylation, cleavage, and oxidation). Over 20 key enzymes from these pathways have been identified that demonstrate the biodiversity and importance of DMSP cycling. The last dozen years have seen significant changes in our understanding of the enzymology and molecular mechanisms of these DMSP cycling enzymes through the application of biochemistry and structural biology. This has yielded more than 10 crystal structures and, in many cases, detailed explanations as to how and why organisms synthesis and metabolize DMSP. In this review, we describe recent progress in biochemical and mechanistic understandings of DMSP synthesis and metabolism, highlighting the important knowledge gleaned and current challenges that warrant further exploration.