LDHactivesite
This is a close-up view of the active site of Lactate Dehydrogenase from the protist Cryptosporidium parvum (PDB ID 2FM3).
The key active site residues R171 and H195 are shown in dark blue, and both the substrate pyruvate (indicated with the label 'Pyr") and the NAD cofactor are shown colored by atom type.