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1qx2

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(New page: 200px<br /><applet load="1qx2" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qx2, resolution 1.44&Aring;" /> '''X-ray Structure of C...)
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[[Image:1qx2.gif|left|200px]]<br /><applet load="1qx2" size="450" color="white" frame="true" align="right" spinBox="true"
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[[Image:1qx2.gif|left|200px]]<br /><applet load="1qx2" size="350" color="white" frame="true" align="right" spinBox="true"
caption="1qx2, resolution 1.44&Aring;" />
caption="1qx2, resolution 1.44&Aring;" />
'''X-ray Structure of Calcium-loaded Calbindomodulin (A Calbindin D9k Re-engineered to Undergo a Conformational Opening) at 1.44 A Resolution'''<br />
'''X-ray Structure of Calcium-loaded Calbindomodulin (A Calbindin D9k Re-engineered to Undergo a Conformational Opening) at 1.44 A Resolution'''<br />
==Overview==
==Overview==
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The extent of conformational change that calcium binding induces in, EF-hand proteins is a key biochemical property specifying Ca(2+) sensor, versus signal modulator function. To understand how differences in amino, acid sequence lead to differences in the response to Ca(2+) binding, comparative analyses of sequence and structures, combined with model, building, were used to develop hypotheses about which amino acid residues, control Ca(2+)-induced conformational changes. These results were used to, generate a first design of calbindomodulin (CBM-1), a calbindin D(9k), re-engineered with 15 mutations to respond to Ca(2+) binding with a, conformational change similar to that of calmodulin. The gene for CBM-1, was synthesized, and the protein was expressed and purified. Remarkably, this protein did not exhibit any non-native-like molten globule properties, despite the large number of mutations and the nonconservative nature of, some of them. Ca(2+)-induced changes in CD intensity and in the binding of, the hydrophobic probe, ANS, implied that CBM-1 does undergo Ca(2+), sensorlike conformational changes. The X-ray crystal structure of, Ca(2+)-CBM-1 determined at 1.44 A resolution reveals the anticipated, increase in hydrophobic surface area relative to the wild-type protein. A, nascent calmodulin-like hydrophobic docking surface was also found, though, it is occluded by the inter-EF-hand loop. The results from this first, calbindomodulin design are discussed in terms of progress toward, understanding the relationships between amino acid sequence, protein, structure, and protein function for EF-hand CaBPs, as well as the, additional mutations for the next CBM design.
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The extent of conformational change that calcium binding induces in EF-hand proteins is a key biochemical property specifying Ca(2+) sensor versus signal modulator function. To understand how differences in amino acid sequence lead to differences in the response to Ca(2+) binding, comparative analyses of sequence and structures, combined with model building, were used to develop hypotheses about which amino acid residues control Ca(2+)-induced conformational changes. These results were used to generate a first design of calbindomodulin (CBM-1), a calbindin D(9k) re-engineered with 15 mutations to respond to Ca(2+) binding with a conformational change similar to that of calmodulin. The gene for CBM-1 was synthesized, and the protein was expressed and purified. Remarkably, this protein did not exhibit any non-native-like molten globule properties despite the large number of mutations and the nonconservative nature of some of them. Ca(2+)-induced changes in CD intensity and in the binding of the hydrophobic probe, ANS, implied that CBM-1 does undergo Ca(2+) sensorlike conformational changes. The X-ray crystal structure of Ca(2+)-CBM-1 determined at 1.44 A resolution reveals the anticipated increase in hydrophobic surface area relative to the wild-type protein. A nascent calmodulin-like hydrophobic docking surface was also found, though it is occluded by the inter-EF-hand loop. The results from this first calbindomodulin design are discussed in terms of progress toward understanding the relationships between amino acid sequence, protein structure, and protein function for EF-hand CaBPs, as well as the additional mutations for the next CBM design.
==About this Structure==
==About this Structure==
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1QX2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CA and ZN as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1QX2 OCA].
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1QX2 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QX2 OCA].
==Reference==
==Reference==
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[[Category: Bos taurus]]
[[Category: Bos taurus]]
[[Category: Single protein]]
[[Category: Single protein]]
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[[Category: Bunick, C.G.]]
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[[Category: Bunick, C G.]]
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[[Category: Bunick, G.J.]]
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[[Category: Bunick, G J.]]
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[[Category: Chazin, W.J.]]
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[[Category: Chazin, W J.]]
[[Category: Mangahas, S.]]
[[Category: Mangahas, S.]]
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[[Category: Mizoue, L.S.]]
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[[Category: Mizoue, L S.]]
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[[Category: Nelson, M.R.]]
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[[Category: Nelson, M R.]]
[[Category: CA]]
[[Category: CA]]
[[Category: ZN]]
[[Category: ZN]]
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[[Category: protein engineering]]
[[Category: protein engineering]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 01:05:01 2007''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:37 2008''

Revision as of 12:44, 21 February 2008

Image:1qx2.gif

1qx2, resolution 1.44Å

Drag the structure with the mouse to rotate

X-ray Structure of Calcium-loaded Calbindomodulin (A Calbindin D9k Re-engineered to Undergo a Conformational Opening) at 1.44 A Resolution

Overview

The extent of conformational change that calcium binding induces in EF-hand proteins is a key biochemical property specifying Ca(2+) sensor versus signal modulator function. To understand how differences in amino acid sequence lead to differences in the response to Ca(2+) binding, comparative analyses of sequence and structures, combined with model building, were used to develop hypotheses about which amino acid residues control Ca(2+)-induced conformational changes. These results were used to generate a first design of calbindomodulin (CBM-1), a calbindin D(9k) re-engineered with 15 mutations to respond to Ca(2+) binding with a conformational change similar to that of calmodulin. The gene for CBM-1 was synthesized, and the protein was expressed and purified. Remarkably, this protein did not exhibit any non-native-like molten globule properties despite the large number of mutations and the nonconservative nature of some of them. Ca(2+)-induced changes in CD intensity and in the binding of the hydrophobic probe, ANS, implied that CBM-1 does undergo Ca(2+) sensorlike conformational changes. The X-ray crystal structure of Ca(2+)-CBM-1 determined at 1.44 A resolution reveals the anticipated increase in hydrophobic surface area relative to the wild-type protein. A nascent calmodulin-like hydrophobic docking surface was also found, though it is occluded by the inter-EF-hand loop. The results from this first calbindomodulin design are discussed in terms of progress toward understanding the relationships between amino acid sequence, protein structure, and protein function for EF-hand CaBPs, as well as the additional mutations for the next CBM design.

About this Structure

1QX2 is a Single protein structure of sequence from Bos taurus with and as ligands. Full crystallographic information is available from OCA.

Reference

Designing sequence to control protein function in an EF-hand protein., Bunick CG, Nelson MR, Mangahas S, Hunter MJ, Sheehan JH, Mizoue LS, Bunick GJ, Chazin WJ, J Am Chem Soc. 2004 May 19;126(19):5990-8. PMID:15137763

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