Skip to main content
. Author manuscript; available in PMC: 2022 Dec 19.
Published in final edited form as: Biochem J. 2021 Oct 15;478(19):3575–3596. doi: 10.1042/BCJ20210533

Figure 1. Chemistry and biochemical functions of phosphohistidine.

Figure 1.

(A) Histidine undergoes phosphorylation on N1 and N3 to form 1-pHis and 3-pHis, respectively. 1,3 diphosphohistidine can also be formed upon His phosphorylation in vitro. (B) Some metabolic enzymes use a catalytic His to accept a phosphoryl group from a donor before transferring it onto an acceptor, thus acting as enzyme intermediate (upper panel). Histidine kinase (HK) undergoes phosphorylation on the active site His to generate pHis and then transfers the phosphoryl group onto a His in a substrate. pHis phosphatases act by hydrolyzing pHis present either in substrates or HKs (lower panel). Created with biorender.com.