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Title
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Crystal structure of an endochitinase from Hordeum vulgare L. seeds.
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Authors
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P.J.Hart,
A.F.Monzingo,
M.P.Ready,
S.R.Ernst,
J.D.Robertus.
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Ref.
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J Mol Biol, 1993,
229,
189-193.
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PubMed id
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Abstract
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Higher plants contain multiple constitutively expressed proteins for defense
against infection by viruses, bacteria, and fungi. One such class of proteins,
the chitinases, are effective antifungal agents because they hydrolyze the
insoluble beta-1,4-linked polymer of N-acetylglucosamine (chitin), which is the
major component of the mycelial cell wall of many fungi. We report here the
three-dimensional, 2.8 A, crystal structure of a 26 kDa endochitinase from
barley (Hordeum vulgare L.) seeds. The 243 amino acid residue molecule is rich
in alpha-helices and has three disulfide bonds. A prominent elongated cleft runs
the length of the molecule, and is presumably the region responsible for
substrate binding and catalysis. Endochitinases from various species of plants
show a high degree of similarity in their amino acid sequences. It is therefore
likely that the barley endochitinase structure can serve as a model for other
plant endochitinases and that catalytic models based on that structure will be
applicable to the entire enzyme family.
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