Comparing the protein dynamics between Y493H and C580Y, we realized that even though both of them possess larger fluctuations in the loop regions but the microscopic origin of the protein dynamics is completely different from each other. In C580Y, Cys580 residue loses a hydrogen bond interaction with Gly533 (Fig. ), while in the case of Y493H the additional hydrogen bond between His493 and Glu426 compacts the protein but with the cost of enhancing the fluctuations of 370 to 390 residues. We observed that the mutation affects the atomistic motion of the residues that are far from the mutated site.