Functions of two methyl-accepting chemotaxis proteins of Pseudoalteromonas arabiensis N1230-9

Abstract:

[Objective] Pseudoalteromonas, an endemic and dominant genus in the ocean, possesses multiple methyl-accepting chemotaxis proteins (MCPs), the functions of which remain unclear. [Methods] The chemotaxis of Pseudoalteromonas arabiensis N1230-9 isolated from surface seawater of the Pacific Ocean towards 23 carbon sources was analyzed by a plate-based assay for swimming motility. Two sCache domain-containing genes (woc28264 and woc27036) encoding MCPs were deleted by homologous recombination. The chemotaxis of the two mutants to 10 carbon sources was then analyzed. [Results] Strain N1230-9 showed obvious chemotaxis to 10 carbon sources: trehalose, maltose, sucrose, N-acetylglucosamine, l-malic acid, sodium acetate, sodium propionate, sodium pyruvate, citric acid, and succinic acid. WOC28264 was a specific chemotactic receptor for l-malic acid and sucrose, while WOC27036 was a specific chemotactic receptor for citric acid and succinic acid. Both WOC28264 and WOC27036 were chemotactic receptors for N-acetylglucosamine and trehalose. [Conclusion] WOC28264 and WOC27036 have overlapping carbon source effectors.