Methylation-Independent Chemotaxis Systems Are the Norm for Gastric-Colonizing <i>Helicobacter</i> Species
Xiaolin Liu, Karen M. Ottemann
Abstract
Chemotaxis signal transduction systems are common in the archaeal and bacterial world, but not all systems contain the same components. The rationale for this system variation remains unknown. In this report, comparative genomics analysis showed that the presence/absence of CheR and CheB is one main variation within the Helicobacter genus, and it is strongly associated with the niche of Helicobacter species: gastric Helicobacter species, which infect animal stomachs, have lost their CheB and CheR, while enterohepatic Helicobacter species, which infect the liver and intestine, retain them. This study not only provides an example that a chemotaxis system variant is associated with particular niches but also proposes that CheB and CheR are new markers distinguishing gastric from enterohepatic Helicobacter species.