1jef
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TURKEY LYSOZYME COMPLEX WITH (GLCNAC)3
OverviewOverview
The turkey-egg lysozyme (TEL) complex with tri-N-acetylchitotriose, [(GlcNac)3] was co-crystallized from 1.5% TEL and 2 mM (GlcNac)3 at pH, 4.2. The crystal structure was determined by molecular replacement and, refined to an R value of 0.182 using 10-1.77 A data. The (GlcNac)3, molecule occupies the subsites A, B and C. At the subsites B and C, the, sugar residues are bound in a similar manner to that found in the hen-egg, lysozyme (HEL) complex. In contrast, the GlcNac residue at the subsite A, is exposed to bulk solvent and has no contact with the protein molecule, because the active residue Asp101 in HEL is replaced by Gly in TEL. A, sulfate ion is bound in the vicinity of subsite B and forms hydrogen bonds, with the sugar residue and the guanidino group of Arg61, assisting the, binding of the sugar residue to subsite B. The active-site cleft of TEL is, narrower than that of native TEL, thus attaining the best fit of the, (GlcNac)3 molecule. The lack of binding ability of subsite A is discussed, in relation to the catalytic properties of TEL. The result suggests that, the cleavage pattern of oligosaccharide substrates in the catalytic, reaction is regulated by the protein-sugar interaction at subsite A.
About this StructureAbout this Structure
1JEF is a Single protein structure of sequence from Meleagris gallopavo with SO4 as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
ReferenceReference
X-ray structure of turkey-egg lysozyme complex with tri-N-acetylchitotriose. Lack of binding ability at subsite A., Harata K, Muraki M, Acta Crystallogr D Biol Crystallogr. 1997 Nov 1;53(Pt 6):650-7. PMID:15299852
Page seeded by OCA on Tue Nov 20 18:09:54 2007