R. pomeroyi also has the ability to degrade dimethylsulfoniopropionate (DMSP), a sulfur-containing algal osmolyte and use the sulfur to synthesize sulfur-containing amino acids. Although many marine bacteria are capable of degrading DMSP, the genes and proteins used to do so were elusive to researchers for many years. It was in R. pomeroyi that Howard and colleagues discovered the first gene that degrades DMSP. This gene (dmdA) codes for a protein (DmdA) that removes a methyl group (-CH3) from DMSP. The DmdA protein has since been further characterized from R. pomeroyi, as well as the transcriptional response of the dmdA gene to the presence of DMSP and the sequence diversity of the dmdA gene. This demethylation process is the first step in the highly sought-after demethylation pathway of DMSP degradation in marine bacteria. Following the discovery of the dmdA gene, the gene sequence was used to establish that over half of marine bacteria, including both open-ocean and coastal bacteria, are capable of demethylating DMSP.
