Partners in crime: phosphotransfer profiling identifies a multicomponent phosphorelay

The first multicomponent phosphorelay, regulating stalk biogenesis, has been identified in Caulobacter crescentus using a bioinformatic screen, targeted disruptions of each histidine kinase and response regulator, and a new technique called phosphotransfer profiling, in which a purified histidine kinase or histidine phosphotransferase is simultaneously assayed for the ability to phosphorylate each purified response regulator protein from one organism. This powerful combination of approaches will allow future researchers to map the interactions among all two-component signal transduction proteins in genetically tractable bacteria with sequenced genomes.