Bacterial chemotaxis is controlled by the histidine kinase CheA and the response regulator CheY. Shannon Wing Au and colleagues of The Chinese University of Hong Kong obtained H. pylori's CheY's crystal structure. "As with E. coli CheY, H. pylori CheY1 interacts with the switch protein FliM," says Au. But a structural comparison of the two showed a major difference between them in the binding surface of FliM, suggesting, says Au, a different bond in the H. pylori version of ChY1-FliM. "On the other hand, we found that CheY-like proteins bind differentially to CheA, helping us understand the diverse responses of these proteins to CheA phosphotransfer activities." Au notes that their study provides the first look at the structure in H. pylori of the proteins involved in chemotaxis. "We are planning to study the structure of other chemotaxis proteins and their complexes in H. pylori, she says. "This work could help us identify the unique feature in the pathway that allows this microbe to colonize the stomach." Her paper notes that H. pylori lives inside roughly 50% of all Homo sapiens.

(K. H. Lam, T. K. W. Ling, and S. W. Au. 2010. Crystal structure of activated CheY1 from Helicobacter pylori. J. Bacteriol. 192:2324-2334.)