Activation of the CheA kinase by asparagine in Bacillus subtilis chemotaxis.

Past experiments have shown that CheA and CheY are required to generate smooth swimming signals in Bacillus subtilis chemotaxis. This study, as anticipated from in vivo experiments, demonstrates in vitro that an attractant-bound chemoreceptor leads to an increase in CheA activity, which in turn leads to an increase in the CheY-P pool that ultimately causes a behavioural change in the bacteria. Asparagine has been found to increase the rate of CheY-P formation in the presence of McpB-containing membranes, CheA, and an excess of CheY. This asparagine effect requires the presence of both CheA and McpB, the latter of which has been shown to be the sole receptor for this attractant. Utilizing membranes from a number of B. subtilis null mutant strains, insight has also been gained into the potential roles of a number of unique chemotaxis proteins in the regulation of CheA activity in the presence and absence of this attractant.