Since histidine kinases are not found in mammalian cells, histidine kinases would be an excellent target for a rational design of antimicrobial drugs. Overall description is that of a sandwich formed by five beta-strands and three alpha helices. One end of the sandwich is blocked by a short beta strand. Also present is a long loop of random coil and a short alpha helix. Thus, it is possible that DNA gyrase B and EnvZ are distantly related in evolutionary scale.
Longer coil is the N-terminus of each polypeptide chain.
The turn section is made up of nine residues. The two polypeptide chains are held together with many hydrophobic residues between the two.