1r9l
From Proteopedia
(New page: 200px<br /><applet load="1r9l" size="450" color="white" frame="true" align="right" spinBox="true" caption="1r9l, resolution 1.59Å" /> '''structure analysis o...) |
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| - | [[Image:1r9l.gif|left|200px]]<br /><applet load="1r9l" size=" | + | [[Image:1r9l.gif|left|200px]]<br /><applet load="1r9l" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1r9l, resolution 1.59Å" /> | caption="1r9l, resolution 1.59Å" /> | ||
'''structure analysis of ProX in complex with glycine betaine'''<br /> | '''structure analysis of ProX in complex with glycine betaine'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Compatible solutes such as glycine betaine and proline betaine are | + | Compatible solutes such as glycine betaine and proline betaine are accumulated to exceedingly high intracellular levels by many organisms in response to high osmolarity to offset the loss of cell water. They are excluded from the immediate hydration shell of proteins and thereby stabilize their native structure. Despite their exclusion from protein surfaces, the periplasmic ligand-binding protein ProX from the Escherichia coli ATP-binding cassette transport system ProU binds the compatible solutes glycine betaine and proline betaine with high affinity and specificity. To understand the mechanism of compatible solute binding, we determined the high resolution structure of ProX in complex with its ligands glycine betaine and proline betaine. This crystallographic study revealed that cation-pi interactions between the positive charge of the quaternary amine of the ligands and three tryptophan residues forming a rectangular aromatic box are the key determinants of the high affinity binding of compatible solutes by ProX. The structural analysis was combined with site-directed mutagenesis of the ligand binding pocket to estimate the contributions of the tryptophan residues involved in binding. |
==About this Structure== | ==About this Structure== | ||
| - | 1R9L 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 UNX and BET as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1R9L 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=UNX:'>UNX</scene> and <scene name='pdbligand=BET:'>BET</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R9L OCA]. |
==Reference== | ==Reference== | ||
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[[Category: tryptophan box]] | [[Category: tryptophan box]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:48:35 2008'' |
Revision as of 12:48, 21 February 2008
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structure analysis of ProX in complex with glycine betaine
Overview
Compatible solutes such as glycine betaine and proline betaine are accumulated to exceedingly high intracellular levels by many organisms in response to high osmolarity to offset the loss of cell water. They are excluded from the immediate hydration shell of proteins and thereby stabilize their native structure. Despite their exclusion from protein surfaces, the periplasmic ligand-binding protein ProX from the Escherichia coli ATP-binding cassette transport system ProU binds the compatible solutes glycine betaine and proline betaine with high affinity and specificity. To understand the mechanism of compatible solute binding, we determined the high resolution structure of ProX in complex with its ligands glycine betaine and proline betaine. This crystallographic study revealed that cation-pi interactions between the positive charge of the quaternary amine of the ligands and three tryptophan residues forming a rectangular aromatic box are the key determinants of the high affinity binding of compatible solutes by ProX. The structural analysis was combined with site-directed mutagenesis of the ligand binding pocket to estimate the contributions of the tryptophan residues involved in binding.
About this Structure
1R9L is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.
Reference
Cation-pi interactions as determinants for binding of the compatible solutes glycine betaine and proline betaine by the periplasmic ligand-binding protein ProX from Escherichia coli., Schiefner A, Breed J, Bosser L, Kneip S, Gade J, Holtmann G, Diederichs K, Welte W, Bremer E, J Biol Chem. 2004 Feb 13;279(7):5588-96. Epub 2003 Nov 11. PMID:14612446
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