Identification of DMS receptors in the marine Alcaligenes faecalis J481

Abstract:

[Objective] β-dimethylsulfoniopropionate (DMSP), an important sulfur-containing organic compound in the marine environment, is the main precursor to the climatically important gas dimethyl sulfide (DMS). DMS is released upon the bacterial catabolism of DMSP. The biological significance of this reaction is still unclear, and studies have shown that DMSP might be a chemoattractant. This study aims to identify the signal molecule in the chemotaxis of Alcaligenes faecalis J481 to DMSP and the receptor gene in this process. [Methods] All genes encoding methyl-accepting chemotaxis protein (MCP) were explored by genome mining, and the structures and functions of the chemotaxis receptors were predicted. The receptors-deleted mutants were developed by homologous recombination. The chemotactic phenotypes were observed based on the soft agar plate experiment and the chemotaxis receptors of DMS were determined. [Results] Through the test of DMSP, DMS, and acrylic acid, it was found that the signal molecule in the chemotaxis was DMS. A total of 8 potential genes encoding chemotaxis receptor proteins were found from the genome of J481, and D6I95_17420 was identified to encode the receptor protein of DMS. [Conclusion] D6I95_17420 encodes the chemotaxis receptor protein of DMS, which lays a foundation for further exploring the regulatory effect of DMS as a signal molecule in cells.