Entry retrieved from the Protein Data
Bank at RCSB.
1LMQ: Hydrolase (O-Glycosyl). Date: Oct 25, 1994.
Authors: S.Karlsen, E.Hough
Compound: Lysozyme. Source: Oncorhynchus Mykiss.
Ligand: Tetra-N-Acetylglucosamine (Tetra NAG)
Method: X-Ray Diffraction. Resolution:1.6 Ang.
Lysozyme is an enzyme that facilitates the destruction of cell walls
that are composed of alternating NAM (N-acetylmuramic acid) and NAG
(N-acetylglucosamine) units. Lysozyme does so by way of electrostatic
catalysis of NAM-NAG bond cleavage. Asp 52 and Glu 35 are key to the
catalytic action: (1) Asp 52 (shown in spacefill) contains a
carboxylate side chain and its
negative charge stabilizes the incipient positive charge on NAM in the
cleavage. (2) Glu 35 (shown in spacefill) contains a carboxylic acid
side chain and this acid
acts as a general acid catalyst. Find Asp 52 and Glu 35 in the binding
pocket.