Widespread bacterial protein histidine phosphorylation revealed by mass spectrometry-based proteomics

A twist on a common method used for enriching phosphorylated peptides for mass spectrometry-based proteomics analysis now reveals previously undetected and widespread histidine phosphorylation in Escherichia coli. For decades, major difficulties in analyzing histidine phosphorylation have limited the study of phosphohistidine signaling. Here we report a method revealing widespread and abundant protein histidine phosphorylation in Escherichia coli. We generated an extensive E. coli phosphoproteome data set, in which a remarkably high percentage (∼10%) of phosphorylation sites are phosphohistidine sites. This resource should help enable a better understanding of the biological function of histidine phosphorylation.