Namely, the carbonyl of Pro401 is strongly hydrogen bonded (ρ=0.04178) to one of the amino hydrogens of Lys353 (i.e., O18-H32). We expect that this hydrogen bond will stabilize the conformation of Lys353 so that Lys353 is strongly hydrogen bonded to the equatorial oxygen (O2) of vanadate; a QM study of the mechanism has shown that this hydrogen bond between