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2d3n
From Proteopedia
(New page: 200px<br /><applet load="2d3n" size="450" color="white" frame="true" align="right" spinBox="true" caption="2d3n, resolution 1.90Å" /> '''Crystal structure of...) |
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| - | [[Image:2d3n.gif|left|200px]]<br /><applet load="2d3n" size=" | + | [[Image:2d3n.gif|left|200px]]<br /><applet load="2d3n" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2d3n, resolution 1.90Å" /> | caption="2d3n, resolution 1.90Å" /> | ||
'''Crystal structure of maltohexaose-producing amylase from Bacillus sp.707 complexed with maltohexaose'''<br /> | '''Crystal structure of maltohexaose-producing amylase from Bacillus sp.707 complexed with maltohexaose'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Maltohexaose-producing amylase (G6-amylase) from alkalophilic Bacillus | + | Maltohexaose-producing amylase (G6-amylase) from alkalophilic Bacillus sp.707 predominantly produces maltohexaose (G6) in the yield of >30% of the total products from short-chain amylose (DP=17). Our previous crystallographic study showed that G6-amylase has nine subsites, from -6 to +3, and pointed out the importance of the indole moiety of Trp140 in G6 production. G6-amylase has very low levels of hydrolytic activities for oligosaccharides shorter than maltoheptaose. To elucidate the mechanism underlying G6 production, we determined the crystal structures of the G6-amylase complexes with G6 and maltopentaose (G5). In the active site of the G6-amylase/G5 complex, G5 is bound to subsites -6 to -2, while G1 and G6 are found at subsites +2 and -7 to -2, respectively, in the G6-amylase/G6 complex. In both structures, the glucosyl residue located at subsite -6 is stacked to the indole moiety of Trp140 within a distance of 4A. The measurement of the activities of the mutant enzymes when Trp140 was replaced by leucine (W140L) or by tyrosine (W140Y) showed that the G6 production from short-chain amylose by W140L is lower than that by W140Y or wild-type enzyme. The face-to-face short contact between Trp140 and substrate sugars is suggested to regulate the disposition of the glucosyl residue at subsite -6 and to govern product specificity for G6 production. |
==About this Structure== | ==About this Structure== | ||
| - | 2D3N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.] with GLC, CA and NA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glucan_1,4-alpha-maltohexaosidase Glucan 1,4-alpha-maltohexaosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.98 3.2.1.98] Full crystallographic information is available from [http:// | + | 2D3N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.] with <scene name='pdbligand=GLC:'>GLC</scene>, <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glucan_1,4-alpha-maltohexaosidase Glucan 1,4-alpha-maltohexaosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.98 3.2.1.98] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2D3N OCA]. |
==Reference== | ==Reference== | ||
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[[Category: protein-carbohydrate complex]] | [[Category: protein-carbohydrate complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:55:02 2008'' |
Revision as of 14:55, 21 February 2008
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Crystal structure of maltohexaose-producing amylase from Bacillus sp.707 complexed with maltohexaose
Overview
Maltohexaose-producing amylase (G6-amylase) from alkalophilic Bacillus sp.707 predominantly produces maltohexaose (G6) in the yield of >30% of the total products from short-chain amylose (DP=17). Our previous crystallographic study showed that G6-amylase has nine subsites, from -6 to +3, and pointed out the importance of the indole moiety of Trp140 in G6 production. G6-amylase has very low levels of hydrolytic activities for oligosaccharides shorter than maltoheptaose. To elucidate the mechanism underlying G6 production, we determined the crystal structures of the G6-amylase complexes with G6 and maltopentaose (G5). In the active site of the G6-amylase/G5 complex, G5 is bound to subsites -6 to -2, while G1 and G6 are found at subsites +2 and -7 to -2, respectively, in the G6-amylase/G6 complex. In both structures, the glucosyl residue located at subsite -6 is stacked to the indole moiety of Trp140 within a distance of 4A. The measurement of the activities of the mutant enzymes when Trp140 was replaced by leucine (W140L) or by tyrosine (W140Y) showed that the G6 production from short-chain amylose by W140L is lower than that by W140Y or wild-type enzyme. The face-to-face short contact between Trp140 and substrate sugars is suggested to regulate the disposition of the glucosyl residue at subsite -6 and to govern product specificity for G6 production.
About this Structure
2D3N is a Single protein structure of sequence from Bacillus sp. with , and as ligands. Active as Glucan 1,4-alpha-maltohexaosidase, with EC number 3.2.1.98 Full crystallographic information is available from OCA.
Reference
Role of Trp140 at subsite -6 on the maltohexaose production of maltohexaose-producing amylase from alkalophilic Bacillus sp.707., Kanai R, Haga K, Akiba T, Yamane K, Harata K, Protein Sci. 2006 Mar;15(3):468-77. Epub 2006 Feb 1. PMID:16452622
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