1d3c: Difference between revisions

Revision as of 13:12, 21 February 2008

MICHAELIS COMPLEX OF BACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE WITH GAMMA-CYCLODEXTRIN

OverviewOverview

The enzyme cyclodextrin glycosyltransferase is closely related to alpha-amylases but has the unique ability to produce cyclodextrins (circular alpha(1-->4)-linked glucoses) from starch. To characterize this specificity we determined a 1.8-A structure of an E257Q/D229N mutant cyclodextrin glycosyltransferase in complex with its product gamma-cyclodextrin, which reveals for the first time how cyclodextrin is competently bound. Across subsites -2, -1, and +1, the cyclodextrin ring binds in a twisted mode similar to linear sugars, giving rise to deformation of its circular symmetry. At subsites -3 and +2, the cyclodextrin binds in a manner different from linear sugars. Sequence comparisons and site-directed mutagenesis experiments support the conclusion that subsites -3 and +2 confer the cyclization activity in addition to subsite -6 and Tyr-195. On this basis, a role of the individual residues during the cyclization reaction cycle is proposed.

About this StructureAbout this Structure

1D3C is a Single protein structure of sequence from Bacillus circulans with and as ligands. Active as Cyclomaltodextrin glucanotransferase, with EC number 2.4.1.19 Full crystallographic information is available from OCA.

ReferenceReference

The cyclization mechanism of cyclodextrin glycosyltransferase (CGTase) as revealed by a gamma-cyclodextrin-CGTase complex at 1.8-A resolution., Uitdehaag JC, Kalk KH, van Der Veen BA, Dijkhuizen L, Dijkstra BW, J Biol Chem. 1999 Dec 3;274(49):34868-76. PMID:10574960

Page seeded by OCA on Thu Feb 21 12:12:33 2008

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OCA

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-[[Image:1d3c.gif|left|200px]]<br /><applet load="1d3c" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1d3c.gif|left|200px]]<br /><applet load="1d3c" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1d3c, resolution 1.78&Aring;" />
 '''MICHAELIS COMPLEX OF BACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE WITH GAMMA-CYCLODEXTRIN'''<br />
 ==Overview==
-The enzyme cyclodextrin glycosyltransferase is closely related to, alpha-amylases but has the unique ability to produce cyclodextrins, (circular alpha(1--&gt;4)-linked glucoses) from starch. To characterize this, specificity we determined a 1.8-A structure of an E257Q/D229N mutant, cyclodextrin glycosyltransferase in complex with its product, gamma-cyclodextrin, which reveals for the first time how cyclodextrin is, competently bound. Across subsites -2, -1, and +1, the cyclodextrin ring, binds in a twisted mode similar to linear sugars, giving rise to, deformation of its circular symmetry. At subsites -3 and +2, the, cyclodextrin binds in a manner different from linear sugars. Sequence, comparisons and site-directed mutagenesis experiments support the, conclusion that subsites -3 and +2 confer the cyclization activity in, addition to subsite -6 and Tyr-195. On this basis, a role of the, individual residues during the cyclization reaction cycle is proposed.
+The enzyme cyclodextrin glycosyltransferase is closely related to alpha-amylases but has the unique ability to produce cyclodextrins (circular alpha(1--&gt;4)-linked glucoses) from starch. To characterize this specificity we determined a 1.8-A structure of an E257Q/D229N mutant cyclodextrin glycosyltransferase in complex with its product gamma-cyclodextrin, which reveals for the first time how cyclodextrin is competently bound. Across subsites -2, -1, and +1, the cyclodextrin ring binds in a twisted mode similar to linear sugars, giving rise to deformation of its circular symmetry. At subsites -3 and +2, the cyclodextrin binds in a manner different from linear sugars. Sequence comparisons and site-directed mutagenesis experiments support the conclusion that subsites -3 and +2 confer the cyclization activity in addition to subsite -6 and Tyr-195. On this basis, a role of the individual residues during the cyclization reaction cycle is proposed.
 ==About this Structure==
-D3C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_circulans Bacillus circulans] with CA and MPD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cyclomaltodextrin_glucanotransferase Cyclomaltodextrin glucanotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.19 2.4.1.19] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1D3C OCA].
+D3C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_circulans Bacillus circulans] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=MPD:'>MPD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Cyclomaltodextrin_glucanotransferase Cyclomaltodextrin glucanotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.19 2.4.1.19] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D3C OCA].
 ==Reference==
@@ Line 15: / Line 15: @@
 [[Category: Single protein]]
 [[Category: Dijkhuizen, L.]]
-[[Category: Dijkstra, B.W.]]
+[[Category: Dijkstra, B W.]]
-[[Category: Kalk, K.H.]]
+[[Category: Kalk, K H.]]
-[[Category: Uitdehaag, J.C.M.]]
+[[Category: Uitdehaag, J C.M.]]
-[[Category: Veen, B.A.van.der.]]
+[[Category: Veen, B A.van der.]]
 [[Category: CA]]
 [[Category: MPD]]
@@ Line 29: / Line 29: @@
 [[Category: transglycosylation]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:58:57 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:12:33 2008''