1DED

CRYSTAL STRUCTURE OF ALKALOPHILIC ASPARAGINE 233-REPLACED CYCLODEXTRIN GLUCANOTRANSFERASE COMPLEXED WITH AN INHIBITOR, ACARBOSE, AT 2.0 A RESOLUTION

Summary for 1DED

• Entry DOI: 10.2210/pdb1ded/pdb
• Related: 1D7F 1PAM
• Related PRD ID: PRD_900022
• Descriptor: CYCLODEXTRIN GLUCANOTRANSFERASE, 4,6-dideoxy-4-{[(1S,4R,5S,6S)-4,5,6-trihydroxy-3-(hydroxymethyl)cyclohex-2-en-1-yl]amino}-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-beta-D-glucopyranose, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: cyclodextrin glucanotransferase, cgtase, acarbose, transferase
• Biological source: Bacillus sp.
• Total number of polymer chains: 2
• Total formula weight: 152509.21

Authors

Ishii, N.,Haga, K.,Yamane, K.,Harata, K. (deposition date: 1999-11-14, release date: 2000-04-07, Last modification date: 2024-10-09)

Primary citation

Ishii, N.,Haga, K.,Yamane, K.,Harata, K.
Crystal structure of alkalophilic asparagine 233-replaced cyclodextrin glucanotransferase complexed with an inhibitor, acarbose, at 2.0 A resolution.
J.Biochem.(Tokyo), 127:383-391, 2000

PubMed Abstract: 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.

PubMed: 10731709

Experimental method

X-RAY DIFFRACTION (2 Å)