Reconstitution of the bacterial chemotaxis signal transduction system from purified components.

摘要: In bacterial chemotaxis, transmembrane receptor proteins detect attractants and repellents in the medium send intracellular signals that control motility. The cytoplasmic transduce information from receptors to flagellar motor have previously been purified many of their enzymatic activities identified. Here we report reconstitution complete signal transduction system components. protein kinase, CheA, plays a central role both initial excitation response stimuli as well subsequent events associated with adaptation. This kinase provides phosphoryl groups two acceptor proteins, CheY, which interacts motor, CheB, demethylates receptors. aspartate receptor, Tar, reconstituted into phospholipid vesicles, acts conjunction an auxiliary protein, CheW, stimulate rate autophosphorylation greater than 10-fold. stimulation is inhibited by aspartate. activity increased levels methylation. effect mechanism explains how changes methylation mediate adaptive responses attractant repellant stimuli.