In enzymology, a protein-histidine tele-kinase is an enzyme that catalyzes the chemical reaction ATP + protein L-histidine ⇌ {\displaystyle \rightleftharpoons } ADP + protein Nτ-phospho-L-histidineThus, the two substrates of this enzyme are ATP and protein L-histidine, whereas its two products are ADP and protein Ntau-phospho-L-histidine. Wikipedia