1exp: Difference between revisions

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==Overview==
==Overview==
The three-dimensional structure of a catalytically competent, glycosyl-enzyme intermediate of a retaining beta-1,4-glycanase has been, determined at a resolution of 1.8 A by X-ray diffraction. A fluorinated, slow substrate forms an alpha-D-glycopyranosyl linkage to one of the two, invariant carboxylates, Glu 233, as supported in solution by 19F-NMR, studies. The resulting ester linkage is coplanar with the cyclic oxygen of, the proximal saccharide and is inferred to form a strong hydrogen bond, with the 2-hydroxyl of that saccharide unit in natural substrates. The, active-site architecture of this covalent intermediate gives insights into, both the classical double-displacement catalytic mechanism and the basis, for the enzyme's specificity.
The three-dimensional structure of a catalytically competent glycosyl-enzyme intermediate of a retaining beta-1,4-glycanase has been determined at a resolution of 1.8 A by X-ray diffraction. A fluorinated slow substrate forms an alpha-D-glycopyranosyl linkage to one of the two invariant carboxylates, Glu 233, as supported in solution by 19F-NMR studies. The resulting ester linkage is coplanar with the cyclic oxygen of the proximal saccharide and is inferred to form a strong hydrogen bond with the 2-hydroxyl of that saccharide unit in natural substrates. The active-site architecture of this covalent intermediate gives insights into both the classical double-displacement catalytic mechanism and the basis for the enzyme's specificity.


==About this Structure==
==About this Structure==
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[[Category: Cellulomonas fimi]]
[[Category: Cellulomonas fimi]]
[[Category: Single protein]]
[[Category: Single protein]]
[[Category: Johns, K.L.]]
[[Category: Johns, K L.]]
[[Category: Rose, D.R.]]
[[Category: Rose, D R.]]
[[Category: Tull, D.]]
[[Category: Tull, D.]]
[[Category: White, A.]]
[[Category: White, A.]]
[[Category: Withers, S.G.]]
[[Category: Withers, S G.]]
[[Category: cellulose degradation]]
[[Category: cellulose degradation]]
[[Category: glycosidase]]
[[Category: glycosidase]]
Line 24: Line 24:
[[Category: signal]]
[[Category: signal]]


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