1ded
From Proteopedia
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| , resolution 2.0Å | |||||||
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| Ligands: | , | ||||||
| Activity: | Cyclomaltodextrin glucanotransferase, with EC number 2.4.1.19 | ||||||
| Related: | 1D7F, 1PAM
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF ALKALOPHILIC ASPARAGINE 233-REPLACED CYCLODEXTRIN GLUCANOTRANSFERASE COMPLEXED WITH AN INHIBITOR, ACARBOSE, AT 2.0 A RESOLUTION
Overview
The product specificity of cyclodextrin glucanotransferase (CGTase) from alkalophilic Bacillus sp. #1011 is improved to near-uniformity by mutation of histidine-233 to asparagine. Asparagine 233-replaced CGTase (H233N-CGTase) no longer produces alpha-cyclodextrin, while the wild-type CGTase from the same bacterium produces a mixture of predominantly alpha-, beta-, and gamma-cyclodextrins, catalyzing the conversion of starch into cyclic or linear alpha-1,4-linked glucopyranosyl chains. In order to better understand the protein engineering of H233N-CGTase, the crystal structure of the mutant enzyme complexed with a maltotetraose analog, acarbose, was determined at 2.0 A resolution with a final crystallographic R value of 0.163 for all data. Taking a close look at the active site cleft in which the acarbose molecule is bound, the most probable reason for the improved specificity of H233N-CGTase is the removal of interactions needed to form a compact ring like a-cyclodextrin.
About this Structure
1DED is a Single protein structure of sequence from Bacillus sp.. Full crystallographic information is available from OCA.
Reference
Crystal structure of alkalophilic asparagine 233-replaced cyclodextrin glucanotransferase complexed with an inhibitor, acarbose, at 2.0 A resolution., Ishii N, Haga K, Yamane K, Harata K, J Biochem. 2000 Mar;127(3):383-91. PMID:10731709
Page seeded by OCA on Sun Mar 30 19:39:58 2008
