InterPro domain: IPR028896

Dimethlysulfonioproprionate (DMS) is catabolised in marine bacterioplankton through a pathway in which the initial step involves demethylation to methylmercaptopropionate (MMPA), which is then further catabolised to methane thiol and acetate. The enzyme responsible for the first step is dimethylsulfonioproprionate demethylase DmdA [ 1 , 2 ].

The overall fold of DmdA is not similar to other enzymes that typically utilise the cofactor tetrahydrofolate (THF). Instead DmdA has a triple domain structure similar to that observed for the glycine cleavage T protein [ 3 ]. Glycine cleavage T protein is an aminomethyltransferase 2.1.2.10 which is part of the glycine cleavage complex responsible for the reversible oxidation of glycine [ 4 ].

This entry also includes YgfZ, which is a folate-binding protein [ 5 ] involved in regulating the level of ATP-dnaA and in the modification of some tRNAs. It is probably a key factor in regulatory networks that act via tRNA modification, such as initiation of chromosomal replication [ 6 ].

1. Novel pathway for assimilation of dimethylsulphoniopropionate widespread in marine bacteria. Nature 473, 208-11
2. Bacterial Catabolism of Dimethylsulfoniopropionate (DMSP). Front Microbiol 2, 172
3. Structures of dimethylsulfoniopropionate-dependent demethylase from the marine organism Pelagabacter ubique. Protein Sci. 21, 289-98
4. Crystal structure of aminomethyltransferase in complex with dihydrolipoyl-H-protein of the glycine cleavage system: implications for recognition of lipoyl protein substrate, disease-related mutations, and reaction mechanism. J. Biol. Chem. 285, 18684-92
5. Crystal structure of the YgfZ protein from Escherichia coli suggests a folate-dependent regulatory role in one-carbon metabolism. J. Bacteriol. 186, 7134-40
6. Involvement of the Escherichia coli folate-binding protein YgfZ in RNA modification and regulation of chromosomal replication initiation. Mol. Microbiol. 59, 265-75