The functioning of a catalytic triad is a well-coordinated process. The serine residue acts as a nucleophile, initiating the reaction by attacking the carbonyl carbon of the substrate. The histidine residue acts as a general base, facilitating the deprotonation of the serine's hydroxyl group, thus increasing its nucleophilicity. Meanwhile, the aspartate (or glutamate) residue stabilizes the positively charged histidine through hydrogen bonding or ionic interactions, ensuring the proper orientation and charge distribution within the active site.
