1glg
From Proteopedia
(New page: 200px<br /><applet load="1glg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1glg, resolution 2.0Å" /> '''CRYSTALLOGRAPHIC ANAL...) |
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caption="1glg, resolution 2.0Å" /> | caption="1glg, resolution 2.0Å" /> | ||
'''CRYSTALLOGRAPHIC ANALYSIS OF THE EPIMERIC AND ANOMERIC SPECIFICITY OF THE PERIPLASMIC TRANSPORT(SLASH)CHEMOTACTIC PROTEIN RECEPTOR FOR D-GLUCOSE AND D-GALACTOSE'''<br /> | '''CRYSTALLOGRAPHIC ANALYSIS OF THE EPIMERIC AND ANOMERIC SPECIFICITY OF THE PERIPLASMIC TRANSPORT(SLASH)CHEMOTACTIC PROTEIN RECEPTOR FOR D-GLUCOSE AND D-GALACTOSE'''<br /> | ||
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| + | ==Overview== | ||
| + | The D-glucose/D-galactose-binding protein (M(r) = 33,000) found in the periplasm of bacterial cells serves as the primary high-affinity receptor of active transport for and chemotaxis toward both sugar epimers. This protein from Escherichia coli binds D-glucose with a Kd of 2 x 10(-7) M, which is about 2 times tighter than D-galactose. The 2.0-A resolution crystal structure of the binding protein complexed with D-galactose has been refined to a crystallographic R-factor of 0.167. This structure, combined with that previously refined for the complex with D-glucose [Vyas, N.K., Vyas., M. N., & Quiocho, F. A. (1988) Science 242, 1290-1295], provides understanding, in atomic detail, of recognition of sugar epimers and anomers. In the two complex structures, the sugar ring is positioned identically in the binding site, and each hydroxyl group common to both is involved in very similar cooperative hydrogen-bonding interactions with protein residues and ordered water molecules. Only the beta-anomer of both monosaccharides is bound, with Asp154 OD1 primarily responsible for accepting a hydrogen bond from the anomeric hydroxyl. Recognition of both sugar epimers is accomplished principally by hydrogen bonding of Asp14 OD1 with the equatorial OH4 of D-glucose and OD2 with the axial OH4 of D-galactose. These results are reconciled with equilibrium and fast kinetics data, which indicate binding of both anomers of the two sugars, and further compared with sugar recognition by other periplasmic sugar-binding proteins with specificities for arabinose/galactose/fucose, maltooligosaccharides, and ribose. | ||
==About this Structure== | ==About this Structure== | ||
| - | 1GLG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with GAL and CA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1GLG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=GAL:'>GAL</scene> and <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GLG OCA]. |
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| + | ==Reference== | ||
| + | Crystallographic analysis of the epimeric and anomeric specificity of the periplasmic transport/chemosensory protein receptor for D-glucose and D-galactose., Vyas MN, Vyas NK, Quiocho FA, Biochemistry. 1994 Apr 26;33(16):4762-8. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8161535 8161535] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Quiocho, F | + | [[Category: Quiocho, F A.]] |
| - | [[Category: Vyas, M | + | [[Category: Vyas, M N.]] |
| - | [[Category: Vyas, N | + | [[Category: Vyas, N K.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: GAL]] | [[Category: GAL]] | ||
[[Category: galactose-binding protein]] | [[Category: galactose-binding protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:51:27 2008'' |
Revision as of 10:51, 21 February 2008
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CRYSTALLOGRAPHIC ANALYSIS OF THE EPIMERIC AND ANOMERIC SPECIFICITY OF THE PERIPLASMIC TRANSPORT(SLASH)CHEMOTACTIC PROTEIN RECEPTOR FOR D-GLUCOSE AND D-GALACTOSE
Overview
The D-glucose/D-galactose-binding protein (M(r) = 33,000) found in the periplasm of bacterial cells serves as the primary high-affinity receptor of active transport for and chemotaxis toward both sugar epimers. This protein from Escherichia coli binds D-glucose with a Kd of 2 x 10(-7) M, which is about 2 times tighter than D-galactose. The 2.0-A resolution crystal structure of the binding protein complexed with D-galactose has been refined to a crystallographic R-factor of 0.167. This structure, combined with that previously refined for the complex with D-glucose [Vyas, N.K., Vyas., M. N., & Quiocho, F. A. (1988) Science 242, 1290-1295], provides understanding, in atomic detail, of recognition of sugar epimers and anomers. In the two complex structures, the sugar ring is positioned identically in the binding site, and each hydroxyl group common to both is involved in very similar cooperative hydrogen-bonding interactions with protein residues and ordered water molecules. Only the beta-anomer of both monosaccharides is bound, with Asp154 OD1 primarily responsible for accepting a hydrogen bond from the anomeric hydroxyl. Recognition of both sugar epimers is accomplished principally by hydrogen bonding of Asp14 OD1 with the equatorial OH4 of D-glucose and OD2 with the axial OH4 of D-galactose. These results are reconciled with equilibrium and fast kinetics data, which indicate binding of both anomers of the two sugars, and further compared with sugar recognition by other periplasmic sugar-binding proteins with specificities for arabinose/galactose/fucose, maltooligosaccharides, and ribose.
About this Structure
1GLG is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystallographic analysis of the epimeric and anomeric specificity of the periplasmic transport/chemosensory protein receptor for D-glucose and D-galactose., Vyas MN, Vyas NK, Quiocho FA, Biochemistry. 1994 Apr 26;33(16):4762-8. PMID:8161535
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