Identification of a Catalytic Residue ofClostridium paraputrificumN-Acetyl-β-D-glucosaminidase Nag3A by Site-Directed Mutagenesis

Structural and Kinetic Analysis of Bacillus subtilis N-Acetylglucosaminidase Reveals a Unique Asp-His Dyad Mechanism

“…This contrasts with a study on Clostridium paraputrificum M-21 ␤-N-acetylglucosaminidase (Nag3A). A conserved aspartate residue (Asp 175 ) on the N-terminal domain was proposed as the acid/base catalyst (39) and replacement of Asp 175 with Ala abolished the activity of Nag3A. However, clear kinetic evidence for a role as acid/base catalyst of the above mentioned residue is lacking.…”