Function and evolution of ubiquitous bacterial signaling adapter phosphopeptide recognition domain FHA

Forkhead-associated domain (FHA) is a phosphopeptide recognition domain embedded in some regulatory proteins. With similar fold type to important eukaryotic signaling molecules such as Smad2 and IRF3, the role of bacterial FHA domain is intensively pursued. Reported bacterial FHA domain roles include: regulation of glutamate and lipids production, regulation of cell shape, type III secretion, ethambutol resistance, sporulation, signal transduction, carbohydrate storage and transport, and pathogenic and symbiotic host–bacterium interactions. To provide basis for the studies of other bacterial FHA domain containing proteins, the status of bacterial FHA functionality and evolution were summarized.