1qul
From Proteopedia
(New page: 200px<br /><applet load="1qul" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qul, resolution 1.7Å" /> '''PHOSPHATE-BINDING PRO...) |
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| - | [[Image:1qul.jpg|left|200px]]<br /><applet load="1qul" size=" | + | [[Image:1qul.jpg|left|200px]]<br /><applet load="1qul" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qul, resolution 1.7Å" /> | caption="1qul, resolution 1.7Å" /> | ||
'''PHOSPHATE-BINDING PROTEIN MUTANT WITH ASP 137 REPLACED BY THR COMPLEX WITH CHLORINE AND PHOSPHATE'''<br /> | '''PHOSPHATE-BINDING PROTEIN MUTANT WITH ASP 137 REPLACED BY THR COMPLEX WITH CHLORINE AND PHOSPHATE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Electrostatic interactions are among the key forces determining the | + | Electrostatic interactions are among the key forces determining the structure and function of proteins. These are exemplified in the liganded form of the receptor, a phosphate binding protein from Escherichia coli. The phosphate, completely dehydrated and buried in the receptor, is bound by 12 hydrogen bonds as well as a salt link with Arg 135. We have modulated the ionic attraction while preserving the hydrogen bonds by mutating Asp 137, also salt linked to Arg 135, to Asn, Gly or Thr. High-resolution crystallographic analysis revealed that Gly and Thr (but not Asn) mutant proteins have incorporated a more electronegative Cl- in place of the Asp carboxylate. That no dramatic effect on phosphate affinity was produced by these ionic perturbations indicates a major role for hydrogen bonds and other local dipoles in the binding and charge stabilization of ionic ligands. |
==About this Structure== | ==About this Structure== | ||
| - | 1QUL 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 PO4 and CL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1QUL 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=PO4:'>PO4</scene> and <scene name='pdbligand=CL:'>CL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QUL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Choudhary, A.]] | [[Category: Choudhary, A.]] | ||
| - | [[Category: Ledvina, P | + | [[Category: Ledvina, P S.]] |
| - | [[Category: Quiocho, F | + | [[Category: Quiocho, F A.]] |
[[Category: Yao, N.]] | [[Category: Yao, N.]] | ||
[[Category: CL]] | [[Category: CL]] | ||
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[[Category: phosphate transport]] | [[Category: phosphate transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:43:56 2008'' |
Revision as of 12:43, 21 February 2008
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PHOSPHATE-BINDING PROTEIN MUTANT WITH ASP 137 REPLACED BY THR COMPLEX WITH CHLORINE AND PHOSPHATE
Overview
Electrostatic interactions are among the key forces determining the structure and function of proteins. These are exemplified in the liganded form of the receptor, a phosphate binding protein from Escherichia coli. The phosphate, completely dehydrated and buried in the receptor, is bound by 12 hydrogen bonds as well as a salt link with Arg 135. We have modulated the ionic attraction while preserving the hydrogen bonds by mutating Asp 137, also salt linked to Arg 135, to Asn, Gly or Thr. High-resolution crystallographic analysis revealed that Gly and Thr (but not Asn) mutant proteins have incorporated a more electronegative Cl- in place of the Asp carboxylate. That no dramatic effect on phosphate affinity was produced by these ionic perturbations indicates a major role for hydrogen bonds and other local dipoles in the binding and charge stabilization of ionic ligands.
About this Structure
1QUL is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.
Reference
Modulation of a salt link does not affect binding of phosphate to its specific active transport receptor., Yao N, Ledvina PS, Choudhary A, Quiocho FA, Biochemistry. 1996 Feb 20;35(7):2079-85. PMID:8652549
Page seeded by OCA on Thu Feb 21 14:43:56 2008
