9lyz | pdb_00009lyz
X-RAY CRYSTALLOGRAPHY OF THE BINDING OF THE BACTERIAL CELL WALL TRISACCHARIDE NAM-NAG-NAM TO LYSOZYME
Structural highlights
FunctionLYSC_CHICK Lysozymes have primarily a bacteriolytic function; those in tissues and body fluids are associated with the monocyte-macrophage system and enhance the activity of immunoagents. Has bacteriolytic activity against M.luteus.[1] Publication Abstract from PubMedHen egg white lysozyme was the first enzyme whose structure was determined by X-ray crystallography. The proposed mechanism based on this structure involves the distortion of the saccharide residue (2-acetamido-2-deoxy-D-muramic acid, NAM) in the natural substrate (an alternating beta (1 leads to 4) linked oligomer of 2-acetamido-2-deoxy-D-glucose (NAG) and NAM residues) bound to site D in the binding cleft. The importance of substrate distortion has prompted numerous enzymatic, chemical, theoretical, and physical studies, but there is little direct crystallographic evidence on the conformation of a NAM residue bound at site D. We now present the X-ray structure of the non-hydrolysed trisaccharide NAM-NAG-NAM bound in subsites B, C, D. Our interpretation of the 2.5-A resolution difference map does not involve distortion of this residue in site D. Comparison with the structure of the delta-lactone derived from tetra N-acetylchitotetraose (NAG)3NAL) bound to lysozyme suggests we may be looking at a Michaelis complex. X-ray crystallography of the binding of the bacterial cell wall trisaccharide NAM-NAG-NAM to lysozyme.,Kelly JA, Sielecki AR, Sykes BD, James MN, Phillips DC Nature. 1979 Dec 20-27;282(5741):875-8. PMID:514367[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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