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1ab6
From Proteopedia
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| - | [[Image:1ab6.gif|left|200px]] | + | [[Image:1ab6.gif|left|200px]] |
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| - | '''STRUCTURE OF CHEY MUTANT F14N, V86T''' | + | {{Structure |
| + | |PDB= 1ab6 |SIZE=350|CAPTION= <scene name='initialview01'>1ab6</scene>, resolution 2.20Å | ||
| + | |SITE= | ||
| + | |LIGAND= | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
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| + | '''STRUCTURE OF CHEY MUTANT F14N, V86T''' | ||
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==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1AB6 is a [ | + | 1AB6 is a [[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=1AB6 OCA]. |
==Reference== | ==Reference== | ||
| - | Structure analysis of two CheY mutants: importance of the hydrogen-bond contribution to protein stability., Wilcock D, Pisabarro MT, Lopez-Hernandez E, Serrano L, Coll M, Acta Crystallogr D Biol Crystallogr. 1998 May 1;54(Pt 3):378-85. PMID:[http:// | + | Structure analysis of two CheY mutants: importance of the hydrogen-bond contribution to protein stability., Wilcock D, Pisabarro MT, Lopez-Hernandez E, Serrano L, Coll M, Acta Crystallogr D Biol Crystallogr. 1998 May 1;54(Pt 3):378-85. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9761905 9761905] |
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: sensory transduction]] | [[Category: sensory transduction]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 09:55:19 2008'' |
Revision as of 07:55, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
STRUCTURE OF CHEY MUTANT F14N, V86T
Overview
The crystal structures of two double mutants (F14N/V21T and F14N/V86T) of the signal transduction protein CheY have been determined to a resolution of 2.4 and 2.2 A, respectively. The structures were solved by molecular replacement and refined to final R values of 18.4 and 19.2%, respectively. Together with urea-denaturation experiments the structures have been used to analyse the effects of mutations where hydrophobic residues are replaced by residues capable of establishing hydrogen bonds. The large increase in stabilization (-12.1 kJ mol-1) of the mutation Phe14Asn arises from two factors: a reverse hydrophobic effect and the formation of a good N-cap at alpha-helix 1. In addition, a forward-backward hydrogen-bonding pattern, resembling an N-capping box and involving Asn14 and Arg18, has been found. The two Val to Thr mutations at the hydrophobic core have different thermodynamic effects: the mutation Val21Thr does not affect the stability of the protein while the mutation Val86Thr causes a small destabilization of 1.7 kJ mol-1. At site 21 a backward side chain-to-backbone hydrogen bond is formed inside alpha-helix 1 with the carbonyl O atom of the i - 4 residue without movement of the mutated side chain. The destabilizing effect of introducing a polar group in the core is efficiently compensated for by the formation of an extra hydrogen bond. At site 86 the new Ogamma atom escapes from the hydrophobic environment by a chi1 rotation into an adjacent hydrophilic cavity to form a new hydrogen bond. In this case the isosteric Val to Thr substitution is disruptive but the loss in stabilization energy is partly compensated by the formation of a hydrogen bond. The two crystal structures described in this work underline the significance of the hydrogen-bond component to protein stability.
About this Structure
1AB6 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure analysis of two CheY mutants: importance of the hydrogen-bond contribution to protein stability., Wilcock D, Pisabarro MT, Lopez-Hernandez E, Serrano L, Coll M, Acta Crystallogr D Biol Crystallogr. 1998 May 1;54(Pt 3):378-85. PMID:9761905
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