Exhibited similar substrate specificity to wild-type. The distance between the residue and the catalytic pocket was too far to enable the binding or positioning of a water molecule for hydrolysis activity. On the other hand,and M375I (increased hydrophobicity), which was also located between the third and the fourth conserve region,affected hydrolysis active severly. as shown by a reduction in specific activity. The M375I residue is located close to the active site