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Title
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X-ray structures along the reaction pathway of cyclodextrin glycosyltransferase elucidate catalysis in the alpha-amylase family.
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Authors
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J.C.Uitdehaag,
R.Mosi,
K.H.Kalk,
B.A.van der Veen,
L.Dijkhuizen,
S.G.Withers,
B.W.Dijkstra.
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Ref.
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Nat Struct Biol, 1999,
6,
432-436.
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PubMed id
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Abstract
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Cyclodextrin glycosyltransferase (CGTase) is an enzyme of the alpha-amylase
family, which uses a double displacement mechanism to process alpha-linked
glucose polymers. We have determined two X-ray structures of CGTase complexes,
one with an intact substrate at 2.1 A resolution, and the other with a
covalently bound reaction intermediate at 1.8 A resolution. These structures
give evidence for substrate distortion and the covalent character of the
intermediate and for the first time show, in atomic detail, how catalysis in the
alpha-amylase family proceeds by the concerted action of all active site
residues.
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