CROSS-TALK BETWEEN THE 2-COMPONENT REGULATORY SYSTEMS NODVW AND NWSABOF BRADYRHIZOBIUM-JAPONICUM

The protein products of the Bradyrhizobium japonicum gene pairs nodVW and nwsAB are members of the bacterial two-component regulatory system s. While NodW and NwsB exhibit all of the characteristics of the respo nse-regulator class, NodV and NwsA contain the conserved domain of the sensor-kinase family. Overexpression of the nwsB gene results in comp lementation of the nodulation defect of a nodW mutant. We report here that the NwsB protein, unlike the overproduced NodW protein, requires NodV or NwsA for its function. This shows that cross-talk occurs betwe en NwsAB and NodVW, in that NodV appears to activate NwsB.