1azk
THREE-DIMENSIONAL STRUCTURES OF THREE ENGINEERED CELLULOSE-BINDING DOMAINS OF CELLOBIOHYDROLASE I FROM TRICHODERMA REESEI, NMR, 19 STRUCTURES
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OverviewOverview
Three-dimensional solution structures for three engineered, synthetic CBDs, (Y5A, Y31A, and Y32A) of cellobiohydrolase I (CBHI) from Trichoderma, reesei were studied with nuclear magnetic resonance (NMR) and circular, dichroism (CD) spectroscopy. According to CD measurements the antiparallel, beta-sheet structure of the CBD fold was preserved in all engineered, peptides. The three-dimensional NMR-based structures of Y31A and Y32A, revealed only small local changes due to mutations in the flat face of, CBD, which is expected to bind to crystalline cellulose. Therefore, the, structural roles of Y31 and Y32 are minor, but their functional importance, is obvious because these mutants do not bind strongly to cellulose. In the, case of Y5A, the disruption of the structural framework at the N-terminus, and the complete loss of binding affinity implies that Y5 has both, structural and functional significance. The number of aromatic residues, and their precise spatial arrangement in the flat face of the type I CBD, fold appears to be critical for specific binding. A model for the CBD, binding in which the three aligned aromatic rings stack onto every other, glucose ring of the cellulose polymer is discussed.
About this StructureAbout this Structure
1AZK is a Single protein structure of sequence from Hypocrea jecorina. Active as Cellulose 1,4-beta-cellobiosidase, with EC number 3.2.1.91 Full crystallographic information is available from OCA.
ReferenceReference
Three-dimensional structures of three engineered cellulose-binding domains of cellobiohydrolase I from Trichoderma reesei., Mattinen ML, Kontteli M, Kerovuo J, Linder M, Annila A, Lindeberg G, Reinikainen T, Drakenberg T, Protein Sci. 1997 Feb;6(2):294-303. PMID:9041630
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