2fta
From Proteopedia
(New page: 200px<br /><applet load="2fta" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fta, resolution 1.610Å" /> '''Structure of Cu(II)...) |
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| - | [[Image:2fta.gif|left|200px]]<br /><applet load="2fta" size=" | + | [[Image:2fta.gif|left|200px]]<br /><applet load="2fta" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2fta, resolution 1.610Å" /> | caption="2fta, resolution 1.610Å" /> | ||
'''Structure of Cu(II)azurin with the metal-binding loop sequence "CTFPGHSALM" replaced with "CTPHPFM"'''<br /> | '''Structure of Cu(II)azurin with the metal-binding loop sequence "CTFPGHSALM" replaced with "CTPHPFM"'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The main active-site loop of the copper-binding protein azurin (a | + | The main active-site loop of the copper-binding protein azurin (a cupredoxin) has been shortened from C(112)TFPGH(117)SALM(121) to C(112)TPH(115)PFM(118) (the native loop from the cupredoxin amicyanin) and also to C(112)TPH(115)PM(117). The Cu(II) site structure is almost unaffected by shortening, as is that of the Cu(I) center at alkaline pH in the variant with the C(112)TPH(115)PM(117) loop sequence. Subtle spectroscopic differences due to alterations in the spin density distribution at the Cu(II) site can be attributed mainly to changes in the hydrogen-bonding pattern. Electron transfer is almost unaffected by the introduction of the C(112)TPH(115)PFM(118) loop, but removal of the Phe residue has a sizable effect on reactivity, probably because of diminished homodimer formation. At mildly acidic pH values, the His-115 ligand protonates and dissociates from the cuprous ion, an effect that has a dramatic influence on the reactivity of cupredoxins. These studies demonstrate that the amicyanin loop adopts a conformation identical to that found in the native protein when introduced into azurin, that a shorter than naturally occurring C-terminal active-site loop can support a functional T1 copper site, that CTPHPM is the minimal loop length required for binding this ubiquitous electron transfer center, and that the length and sequence of a metal-binding loop regulates a range of structural and functional features of the active site of a metalloprotein. |
==About this Structure== | ==About this Structure== | ||
| - | 2FTA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa] with CU, 2PE, EOH and PEG as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2FTA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_aeruginosa Pseudomonas aeruginosa] with <scene name='pdbligand=CU:'>CU</scene>, <scene name='pdbligand=2PE:'>2PE</scene>, <scene name='pdbligand=EOH:'>EOH</scene> and <scene name='pdbligand=PEG:'>PEG</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FTA OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Pseudomonas aeruginosa]] | [[Category: Pseudomonas aeruginosa]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Banfield, M | + | [[Category: Banfield, M J.]] |
[[Category: 2PE]] | [[Category: 2PE]] | ||
[[Category: CU]] | [[Category: CU]] | ||
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[[Category: greek-key beta-barrel]] | [[Category: greek-key beta-barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:24:53 2008'' |
Revision as of 15:24, 21 February 2008
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Structure of Cu(II)azurin with the metal-binding loop sequence "CTFPGHSALM" replaced with "CTPHPFM"
Overview
The main active-site loop of the copper-binding protein azurin (a cupredoxin) has been shortened from C(112)TFPGH(117)SALM(121) to C(112)TPH(115)PFM(118) (the native loop from the cupredoxin amicyanin) and also to C(112)TPH(115)PM(117). The Cu(II) site structure is almost unaffected by shortening, as is that of the Cu(I) center at alkaline pH in the variant with the C(112)TPH(115)PM(117) loop sequence. Subtle spectroscopic differences due to alterations in the spin density distribution at the Cu(II) site can be attributed mainly to changes in the hydrogen-bonding pattern. Electron transfer is almost unaffected by the introduction of the C(112)TPH(115)PFM(118) loop, but removal of the Phe residue has a sizable effect on reactivity, probably because of diminished homodimer formation. At mildly acidic pH values, the His-115 ligand protonates and dissociates from the cuprous ion, an effect that has a dramatic influence on the reactivity of cupredoxins. These studies demonstrate that the amicyanin loop adopts a conformation identical to that found in the native protein when introduced into azurin, that a shorter than naturally occurring C-terminal active-site loop can support a functional T1 copper site, that CTPHPM is the minimal loop length required for binding this ubiquitous electron transfer center, and that the length and sequence of a metal-binding loop regulates a range of structural and functional features of the active site of a metalloprotein.
About this Structure
2FTA is a Single protein structure of sequence from Pseudomonas aeruginosa with , , and as ligands. Full crystallographic information is available from OCA.
Reference
Basic requirements for a metal-binding site in a protein: the influence of loop shortening on the cupredoxin azurin., Li C, Yanagisawa S, Martins BM, Messerschmidt A, Banfield MJ, Dennison C, Proc Natl Acad Sci U S A. 2006 May 9;103(19):7258-63. Epub 2006 May 1. PMID:16651527
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