1sw2: Difference between revisions

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New page: left|200px<br /><applet load="1sw2" size="450" color="white" frame="true" align="right" spinBox="true" caption="1sw2, resolution 2.10Å" /> '''Crystal structure of...
 
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[[Image:1sw2.gif|left|200px]]<br /><applet load="1sw2" size="450" color="white" frame="true" align="right" spinBox="true"  
[[Image:1sw2.gif|left|200px]]<br /><applet load="1sw2" size="350" color="white" frame="true" align="right" spinBox="true"  
caption="1sw2, resolution 2.10&Aring;" />
caption="1sw2, resolution 2.10&Aring;" />
'''Crystal structure of ProX from Archeoglobus fulgidus in complex with glycine betaine'''<br />
'''Crystal structure of ProX from Archeoglobus fulgidus in complex with glycine betaine'''<br />


==Overview==
==Overview==
Compatible solutes such as glycine betaine and proline betaine serve as, protein stabilizers because of their preferential exclusion from protein, surfaces. To use extracellular sources of this class of compounds as, osmo-, cryo-, or thermoprotectants, Bacteria and Archaea have developed, high affinity uptake systems of the ATP-binding cassette type. These, transport systems require periplasmic- or extracellular-binding proteins, that are able to bind the transported substance with high affinity., Therefore, binding proteins that bind compatible solutes have to avoid the, exclusion of their ligands within the binding pocket. In the present study, we addressed the question to how compatible solutes can be effectively, bound by a protein at temperatures around 83 degrees C as this is done by, the ligand-binding protein ProX from the hyperthermophilic archaeon, Archaeoglobus fulgidus. We solved the structures of ProX without ligand, and in complex with both of its natural ligands glycine betaine and, proline betaine, as well as in complex with the artificial ligand, trimethylammonium. Cation-pi interactions and non-classical hydrogen bonds, between four tyrosine residues, a main chain carbonyl oxygen, and the, ligand have been identified to be the key determinants in binding the, quaternary amines of the three investigated ligands. The comparison of the, ligand binding sites of ProX from A. fulgidus and the recently solved, structure of ProX from Escherichia coli revealed a very similar solution, for the problem of compatible solute binding, although both proteins share, only a low degree of sequence identity. The residues involved in ligand, binding are functionally equivalent but not conserved in the primary, sequence.
Compatible solutes such as glycine betaine and proline betaine serve as protein stabilizers because of their preferential exclusion from protein surfaces. To use extracellular sources of this class of compounds as osmo-, cryo-, or thermoprotectants, Bacteria and Archaea have developed high affinity uptake systems of the ATP-binding cassette type. These transport systems require periplasmic- or extracellular-binding proteins that are able to bind the transported substance with high affinity. Therefore, binding proteins that bind compatible solutes have to avoid the exclusion of their ligands within the binding pocket. In the present study we addressed the question to how compatible solutes can be effectively bound by a protein at temperatures around 83 degrees C as this is done by the ligand-binding protein ProX from the hyperthermophilic archaeon Archaeoglobus fulgidus. We solved the structures of ProX without ligand and in complex with both of its natural ligands glycine betaine and proline betaine, as well as in complex with the artificial ligand trimethylammonium. Cation-pi interactions and non-classical hydrogen bonds between four tyrosine residues, a main chain carbonyl oxygen, and the ligand have been identified to be the key determinants in binding the quaternary amines of the three investigated ligands. The comparison of the ligand binding sites of ProX from A. fulgidus and the recently solved structure of ProX from Escherichia coli revealed a very similar solution for the problem of compatible solute binding, although both proteins share only a low degree of sequence identity. The residues involved in ligand binding are functionally equivalent but not conserved in the primary sequence.


==About this Structure==
==About this Structure==
1SW2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus_dsm_4304 Archaeoglobus fulgidus dsm 4304] with BET as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1SW2 OCA].  
1SW2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus_dsm_4304 Archaeoglobus fulgidus dsm 4304] with <scene name='pdbligand=BET:'>BET</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SW2 OCA].  


==Reference==
==Reference==
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[[Category: non-classical hydrogen bonds]]
[[Category: non-classical hydrogen bonds]]


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Revision as of 16:05, 21 February 2008

File:1sw2.gif


1sw2, resolution 2.10Å

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Crystal structure of ProX from Archeoglobus fulgidus in complex with glycine betaine

OverviewOverview

Compatible solutes such as glycine betaine and proline betaine serve as protein stabilizers because of their preferential exclusion from protein surfaces. To use extracellular sources of this class of compounds as osmo-, cryo-, or thermoprotectants, Bacteria and Archaea have developed high affinity uptake systems of the ATP-binding cassette type. These transport systems require periplasmic- or extracellular-binding proteins that are able to bind the transported substance with high affinity. Therefore, binding proteins that bind compatible solutes have to avoid the exclusion of their ligands within the binding pocket. In the present study we addressed the question to how compatible solutes can be effectively bound by a protein at temperatures around 83 degrees C as this is done by the ligand-binding protein ProX from the hyperthermophilic archaeon Archaeoglobus fulgidus. We solved the structures of ProX without ligand and in complex with both of its natural ligands glycine betaine and proline betaine, as well as in complex with the artificial ligand trimethylammonium. Cation-pi interactions and non-classical hydrogen bonds between four tyrosine residues, a main chain carbonyl oxygen, and the ligand have been identified to be the key determinants in binding the quaternary amines of the three investigated ligands. The comparison of the ligand binding sites of ProX from A. fulgidus and the recently solved structure of ProX from Escherichia coli revealed a very similar solution for the problem of compatible solute binding, although both proteins share only a low degree of sequence identity. The residues involved in ligand binding are functionally equivalent but not conserved in the primary sequence.

About this StructureAbout this Structure

1SW2 is a Single protein structure of sequence from Archaeoglobus fulgidus dsm 4304 with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Structural basis for the binding of compatible solutes by ProX from the hyperthermophilic archaeon Archaeoglobus fulgidus., Schiefner A, Holtmann G, Diederichs K, Welte W, Bremer E, J Biol Chem. 2004 Nov 12;279(46):48270-81. Epub 2004 Aug 11. PMID:15308642

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