1cxe: Difference between revisions

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[[Image:1cxe.gif|left|200px]]<br /><applet load="1cxe" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1cxe.gif|left|200px]]<br /><applet load="1cxe" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1cxe, resolution 2.1Å" />

'''COMPLEX OF CGTASE WITH MALTOTETRAOSE AT ROOM TEMPERATURE AND PH 9.1 BASED ON DIFFRACTION DATA OF A CRYSTAL SOAKED WITH ALPHA-CYCLODEXTRIN'''<br />

==Overview==

Asp-229, Glu-257, and Asp-328 constitute the catalytic residues in, cyclodextrin glycosyl transferase from Bacillus circulans strain 251. Via, site-directed mutagenesis constructed D229N, E257Q, and D328N mutant, proteins showed a 4,000-60,000-fold reduction of cyclization activity. A, D229N/E257Q double mutant showed a 700,000-fold reduction and was, crystallized for use in soaking experiments with alpha-cyclodextrin., Crystal structures were determined of wild type CGTase soaked at elevated, pH with alpha-cyclodextrin (resolution, 2.1 A) and maltoheptaose (2.4 A)., In addition, structures at cryogenic temperature were solved of the, unliganded enzyme (2.2 A) and of the D229N/E257Q mutant after soaking with, alpha-cyclodextrin (2.6 A). In the crystals soaked in alpha-cyclodextrin, and maltoheptaose, a maltotetraose molecule is observed to bind in the, active site. Residue 229 is at hydrogen bonding distance from the C-6, hydroxyl group of the sugar, which after cleavage will contain the new, reducing end. In the D229N/E257Q double mutant structure, two, alpha-cyclodextrins are observed to replace two maltoses at the E-domain, thus providing structural information on product inhibition via binding to, the enzyme's raw starch binding domain.

Asp-229, Glu-257, and Asp-328 constitute the catalytic residues in cyclodextrin glycosyl transferase from Bacillus circulans strain 251. Via site-directed mutagenesis constructed D229N, E257Q, and D328N mutant proteins showed a 4,000-60,000-fold reduction of cyclization activity. A D229N/E257Q double mutant showed a 700,000-fold reduction and was crystallized for use in soaking experiments with alpha-cyclodextrin. Crystal structures were determined of wild type CGTase soaked at elevated pH with alpha-cyclodextrin (resolution, 2.1 A) and maltoheptaose (2.4 A). In addition, structures at cryogenic temperature were solved of the unliganded enzyme (2.2 A) and of the D229N/E257Q mutant after soaking with alpha-cyclodextrin (2.6 A). In the crystals soaked in alpha-cyclodextrin and maltoheptaose, a maltotetraose molecule is observed to bind in the active site. Residue 229 is at hydrogen bonding distance from the C-6 hydroxyl group of the sugar, which after cleavage will contain the new reducing end. In the D229N/E257Q double mutant structure, two alpha-cyclodextrins are observed to replace two maltoses at the E-domain, thus providing structural information on product inhibition via binding to the enzyme's raw starch binding domain.

==About this Structure==

1CXE 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 MAL and CA 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=1CXE OCA].

1CXE 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=MAL:'>MAL</scene> and <scene name='pdbligand=CA:'>CA</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=1CXE OCA].

==Reference==

Line 14:

[[Category: Cyclomaltodextrin glucanotransferase]]

[[Category: Single protein]]

[[Category: Dijkstra, B.W.]]

[[Category: Dijkstra, B W.]]

[[Category: Knegtel, R.M.A.]]

[[Category: Knegtel, R M.A.]]

[[Category: Strokopytov, B.V.]]

[[Category: Strokopytov, B V.]]

[[Category: CA]]

[[Category: MAL]]

[[Category: glycosyltransferase]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20~~ 12:49:~~34 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:10:54 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1cxe.gif|left|200px]]<br /><applet load="1cxe" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1cxe.gif|left|200px]]<br /><applet load="1cxe" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1cxe, resolution 2.1&Aring;" />
 '''COMPLEX OF CGTASE WITH MALTOTETRAOSE AT ROOM TEMPERATURE AND PH 9.1 BASED ON DIFFRACTION DATA OF A CRYSTAL SOAKED WITH ALPHA-CYCLODEXTRIN'''<br />
 ==Overview==
-Asp-229, Glu-257, and Asp-328 constitute the catalytic residues in, cyclodextrin glycosyl transferase from Bacillus circulans strain 251. Via, site-directed mutagenesis constructed D229N, E257Q, and D328N mutant, proteins showed a 4,000-60,000-fold reduction of cyclization activity. A, D229N/E257Q double mutant showed a 700,000-fold reduction and was, crystallized for use in soaking experiments with alpha-cyclodextrin., Crystal structures were determined of wild type CGTase soaked at elevated, pH with alpha-cyclodextrin (resolution, 2.1 A) and maltoheptaose (2.4 A)., In addition, structures at cryogenic temperature were solved of the, unliganded enzyme (2.2 A) and of the D229N/E257Q mutant after soaking with, alpha-cyclodextrin (2.6 A). In the crystals soaked in alpha-cyclodextrin, and maltoheptaose, a maltotetraose molecule is observed to bind in the, active site. Residue 229 is at hydrogen bonding distance from the C-6, hydroxyl group of the sugar, which after cleavage will contain the new, reducing end. In the D229N/E257Q double mutant structure, two, alpha-cyclodextrins are observed to replace two maltoses at the E-domain, thus providing structural information on product inhibition via binding to, the enzyme's raw starch binding domain.
+Asp-229, Glu-257, and Asp-328 constitute the catalytic residues in cyclodextrin glycosyl transferase from Bacillus circulans strain 251. Via site-directed mutagenesis constructed D229N, E257Q, and D328N mutant proteins showed a 4,000-60,000-fold reduction of cyclization activity. A D229N/E257Q double mutant showed a 700,000-fold reduction and was crystallized for use in soaking experiments with alpha-cyclodextrin. Crystal structures were determined of wild type CGTase soaked at elevated pH with alpha-cyclodextrin (resolution, 2.1 A) and maltoheptaose (2.4 A). In addition, structures at cryogenic temperature were solved of the unliganded enzyme (2.2 A) and of the D229N/E257Q mutant after soaking with alpha-cyclodextrin (2.6 A). In the crystals soaked in alpha-cyclodextrin and maltoheptaose, a maltotetraose molecule is observed to bind in the active site. Residue 229 is at hydrogen bonding distance from the C-6 hydroxyl group of the sugar, which after cleavage will contain the new reducing end. In the D229N/E257Q double mutant structure, two alpha-cyclodextrins are observed to replace two maltoses at the E-domain, thus providing structural information on product inhibition via binding to the enzyme's raw starch binding domain.
 ==About this Structure==
-CXE 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 MAL and CA 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=1CXE OCA].
+CXE 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=MAL:'>MAL</scene> and <scene name='pdbligand=CA:'>CA</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=1CXE OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Cyclomaltodextrin glucanotransferase]]
 [[Category: Single protein]]
-[[Category: Dijkstra, B.W.]]
+[[Category: Dijkstra, B W.]]
-[[Category: Knegtel, R.M.A.]]
+[[Category: Knegtel, R M.A.]]
-[[Category: Strokopytov, B.V.]]
+[[Category: Strokopytov, B V.]]
 [[Category: CA]]
 [[Category: MAL]]
 [[Category: glycosyltransferase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:49:34 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:10:54 2008''