856 / 2024-09-19 16:36:10
Novel dimethylsulfoniopropionate (DMSP) biosynthesis enzymes in diverse marine bacteria, cyanobacteria and abundant algae
dimethylsulfoniopropionate,bloom-forming Pelagophyceae,climate-cooling gas,sulfur cycling
Session 19 - Marine Plankton Ecosystem and Global Climate Change
Abstract Accepted
Jinyan Wang / Ocean University of China
Jonathan Todd / University of East Anglia
Dimethylsulfoniopropionate (DMSP) is an abundant marine organosulfur compound with roles in stress protection, chemotaxis, nutrient and

sulfur cycling and climate regulation. Here we report the discovery of a bifunctional DMSP biosynthesis enzyme, DsyGD, in the transamination

pathway of the rhizobacterium Gynuella sunshinyii and some filamentous cyanobacteria not previously known to produce DMSP. DsyGD produces

DMSP through its N-terminal DsyG methylthiohydroxybutyrate S-methyltransferase and C-terminal DsyD dimethylsulfoniohydroxybutyrate

decarboxylase domains. Phylogenetically distinct DsyG-like proteins, termed DSYE, with methylthiohydroxybutyrate S-methyltransferase

activity were found in diverse and environmentally abundant algae, comprising a mix of low, high and previously unknown DMSP producers. Algae containing DSYE, particularly bloom-forming Pelagophyceae species, were globally more abundant DMSP producers than those with previously described DMSP synthesis genes. This work greatly increases the number and diversity of predicted DMSP-producing organisms and highlights the importance of Pelagophyceae and other DSYE-containing algae in global DMSP production and sulfur cycling.