Polypeptide Requirement of Multicomponent Monooxygenase DsoABCDEF for Dimethyl Sulfide Oxidizing Activity.

In our previous study, the multicomponent monooxygenase DsoABCDEF in Acinetobacter sp. strain 20B was cloned based on its ability to oxidize dimethyl sulfide (DMS) to dimethyl sulfoxide (DMSO) in E. coli cells, which had high sequence similarity with phenol hydroxylase MopKLMNOP in Acinetobacter calcoaceticus NCIB8250, DmpKLMNOP in Pseudomonas sp. CF600 and some other multicomponent monooxygenases. In this study, DsoB, C, D, E, and F were found to be needed for DMS-oxidizing activity in polypeptide requirement experiments, while DsoA was not necessary for it. It was also found that complementation of the deletion mutants lacking DsoC or F with the corresponding Dmp polypeptides supported the DMS-oxidizing activity, while complementation of the deletion mutants lacking any of the oxygenase subunits (DsoB, D, or E) with the corresponding Dmp polypeptides reduced or nullified the activity.