Histidine in enzyme active centers.
D001665:Binding Sites; D004798:Enzymes / Q000378:metabolism*; D006639:Histidine; D007093:Imidazoles; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D014961:X-Ray Diffraction
D004798:Enzymes; D007093:Imidazoles; D006639:Histidine