8abp: Difference between revisions

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[[Image:8abp.jpg|left|200px]]<br /><applet load="8abp" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:8abp.jpg|left|200px]]<br /><applet load="8abp" size="350" color="white" frame="true" align="right" spinBox="true"

caption="8abp, resolution 1.49Å" />

'''SUGAR-BINDING AND CRYSTALLOGRAPHIC STUDIES OF AN ARABINOSE-BINDING PROTEIN MUTANT (MET108LEU) WHICH EXHIBITS ENHANCED AFFINITY AND ALTERED SPECIFICITY'''<br />

==Overview==

In addition to hydrogen bonds, van der Waals forces contribute to the, affinity of protein-carbohydrate interactions. Nonpolar van der Waals, contacts in the complexes of the L-arabinose-binding protein (ABP) with, monosaccharides have been studied by means of site-directed mutagenesis, equilibrium and rapid kinetic binding techniques, and X-ray, crystallography. ABP, a periplasmic transport receptor of Escherichia, coli, binds L-arabinose, D-galactose, and D-fucose with preferential, affinity in the order of Ara greater than Gal much greater than Fuc., Well-refined, high-resolution structures of ABP complexed with the three, sugars revealed that the structural differences in the ABP-sugar complexes, are localized around C5 of the sugars, where the equatorial H of Ara has, been substituted for CH3 (Fuc) or CH2OH (Gal). The side chain of Met108, undergoes a sterically dictated, ligand-specific, conformational change to, optimize nonpolar interactions between its methyl group and the sugar. We, found that the Met108Leu ABP binds Gal tighter than wild-type ABP binds, Ara and exhibits a preference for ligand in the order of Gal much greater, than Fuc greater than Ara. The differences in affinity can be attributed, to differences in the dissociation rates of the ABP-sugar complexes. We, have refined at better than 1.7-A resolution the crystal structures of the, Met108Leu ABP complexed with each of the sugars and offer a molecular, explanation for the altered binding properties.

In addition to hydrogen bonds, van der Waals forces contribute to the affinity of protein-carbohydrate interactions. Nonpolar van der Waals contacts in the complexes of the L-arabinose-binding protein (ABP) with monosaccharides have been studied by means of site-directed mutagenesis, equilibrium and rapid kinetic binding techniques, and X-ray crystallography. ABP, a periplasmic transport receptor of Escherichia coli, binds L-arabinose, D-galactose, and D-fucose with preferential affinity in the order of Ara greater than Gal much greater than Fuc. Well-refined, high-resolution structures of ABP complexed with the three sugars revealed that the structural differences in the ABP-sugar complexes are localized around C5 of the sugars, where the equatorial H of Ara has been substituted for CH3 (Fuc) or CH2OH (Gal). The side chain of Met108 undergoes a sterically dictated, ligand-specific, conformational change to optimize nonpolar interactions between its methyl group and the sugar. We found that the Met108Leu ABP binds Gal tighter than wild-type ABP binds Ara and exhibits a preference for ligand in the order of Gal much greater than Fuc greater than Ara. The differences in affinity can be attributed to differences in the dissociation rates of the ABP-sugar complexes. We have refined at better than 1.7-A resolution the crystal structures of the Met108Leu ABP complexed with each of the sugars and offer a molecular explanation for the altered binding properties.

==About this Structure==

8ABP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=8ABP OCA].

8ABP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8ABP OCA].

==Reference==

Line 13:

[[Category: Escherichia coli]]

[[Category: Single protein]]

[[Category: Quiocho, F.A.]]

[[Category: Quiocho, F A.]]

[[Category: Tesmer, J.J.G.]]

[[Category: Tesmer, J J.G.]]

[[Category: Vermersch, P.S.]]

[[Category: Vermersch, P S.]]

[[Category: binding proteins]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20 15~~:09:~~27 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:17:41 2008''

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@@ Line 1: / Line 1: @@
-[[Image:8abp.jpg|left|200px]]<br /><applet load="8abp" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:8abp.jpg|left|200px]]<br /><applet load="8abp" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="8abp, resolution 1.49&Aring;" />
 '''SUGAR-BINDING AND CRYSTALLOGRAPHIC STUDIES OF AN ARABINOSE-BINDING PROTEIN MUTANT (MET108LEU) WHICH EXHIBITS ENHANCED AFFINITY AND ALTERED SPECIFICITY'''<br />
 ==Overview==
-In addition to hydrogen bonds, van der Waals forces contribute to the, affinity of protein-carbohydrate interactions. Nonpolar van der Waals, contacts in the complexes of the L-arabinose-binding protein (ABP) with, monosaccharides have been studied by means of site-directed mutagenesis, equilibrium and rapid kinetic binding techniques, and X-ray, crystallography. ABP, a periplasmic transport receptor of Escherichia, coli, binds L-arabinose, D-galactose, and D-fucose with preferential, affinity in the order of Ara greater than Gal much greater than Fuc., Well-refined, high-resolution structures of ABP complexed with the three, sugars revealed that the structural differences in the ABP-sugar complexes, are localized around C5 of the sugars, where the equatorial H of Ara has, been substituted for CH3 (Fuc) or CH2OH (Gal). The side chain of Met108, undergoes a sterically dictated, ligand-specific, conformational change to, optimize nonpolar interactions between its methyl group and the sugar. We, found that the Met108Leu ABP binds Gal tighter than wild-type ABP binds, Ara and exhibits a preference for ligand in the order of Gal much greater, than Fuc greater than Ara. The differences in affinity can be attributed, to differences in the dissociation rates of the ABP-sugar complexes. We, have refined at better than 1.7-A resolution the crystal structures of the, Met108Leu ABP complexed with each of the sugars and offer a molecular, explanation for the altered binding properties.
+In addition to hydrogen bonds, van der Waals forces contribute to the affinity of protein-carbohydrate interactions. Nonpolar van der Waals contacts in the complexes of the L-arabinose-binding protein (ABP) with monosaccharides have been studied by means of site-directed mutagenesis, equilibrium and rapid kinetic binding techniques, and X-ray crystallography. ABP, a periplasmic transport receptor of Escherichia coli, binds L-arabinose, D-galactose, and D-fucose with preferential affinity in the order of Ara greater than Gal much greater than Fuc. Well-refined, high-resolution structures of ABP complexed with the three sugars revealed that the structural differences in the ABP-sugar complexes are localized around C5 of the sugars, where the equatorial H of Ara has been substituted for CH3 (Fuc) or CH2OH (Gal). The side chain of Met108 undergoes a sterically dictated, ligand-specific, conformational change to optimize nonpolar interactions between its methyl group and the sugar. We found that the Met108Leu ABP binds Gal tighter than wild-type ABP binds Ara and exhibits a preference for ligand in the order of Gal much greater than Fuc greater than Ara. The differences in affinity can be attributed to differences in the dissociation rates of the ABP-sugar complexes. We have refined at better than 1.7-A resolution the crystal structures of the Met108Leu ABP complexed with each of the sugars and offer a molecular explanation for the altered binding properties.
 ==About this Structure==
-ABP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=8ABP OCA].
+ABP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8ABP OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Escherichia coli]]
 [[Category: Single protein]]
-[[Category: Quiocho, F.A.]]
+[[Category: Quiocho, F A.]]
-[[Category: Tesmer, J.J.G.]]
+[[Category: Tesmer, J J.G.]]
-[[Category: Vermersch, P.S.]]
+[[Category: Vermersch, P S.]]
 [[Category: binding proteins]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 15:09:27 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:17:41 2008''