1ncz
From Proteopedia
 (New page: 200px<br /><applet load="1ncz" size="450" color="white" frame="true" align="right" spinBox="true"  caption="1ncz, resolution 1.8Å" /> '''TROPONIN C'''<br />  ...)  | 
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| - | [[Image:1ncz.gif|left|200px]]<br /><applet load="1ncz" size="  | + | [[Image:1ncz.gif|left|200px]]<br /><applet load="1ncz" size="350" color="white" frame="true" align="right" spinBox="true"   | 
caption="1ncz, resolution 1.8Å" />  | caption="1ncz, resolution 1.8Å" />  | ||
'''TROPONIN C'''<br />  | '''TROPONIN C'''<br />  | ||
==Overview==  | ==Overview==  | ||
| - | The crystal structures of three metal complexes of troponin C (TnC) have  | + | The crystal structures of three metal complexes of troponin C (TnC) have been determined and refined where the two occupied structural Ca(2+) sites in the C domain have been substituted by Mn(2+), Cd(2+) and Tb(3+). The X-ray intensity data were collected to 2.1, 1.8 and 1.8 A resolution, respectively, on the three metal complexes, which are isomorphous with Ca-TnC. The three complexes have r.m.s. deviations of 0.27, 0.25 and 0.35 A, respectively, for all protein atoms, from Ca-TnC. Irrespective of the charge on the metal (+2 or +3), the occupied sites 3 and 4 exhibit a distorted pentagonal bipyramidal coordination, like Ca-TnC, with seven ligands, six from the 12-residue binding loop and the seventh from a water molecule. Mn(2+) at site 4 seems to display a longer distance to one of the carboxyl bidentate ligands representing an intermediate coordination simulating the six-coordinate Mg(2+). The carboxyl O atoms of the bidentate Glu12 are displaced on the side of the equatorial plane passing through the remaining three ligands with one O atom closer to the plane (Delta of 0.11 to 0.76 A) than the other (Delta of 0.93 to 1.38 A). The two axial ligands are an aspartic carboxyl O atom and a water molecule. The metal is displaced (0.18 to 0.56 A) towards the water facing the water channel.  | 
==About this Structure==  | ==About this Structure==  | ||
| - | 1NCZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with TB and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://  | + | 1NCZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] with <scene name='pdbligand=TB:'>TB</scene> and <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NCZ OCA].   | 
==Reference==  | ==Reference==  | ||
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[[Category: Gallus gallus]]  | [[Category: Gallus gallus]]  | ||
[[Category: Single protein]]  | [[Category: Single protein]]  | ||
| - | [[Category: Rao, S  | + | [[Category: Rao, S T.]]  | 
[[Category: Sundaralingam, M.]]  | [[Category: Sundaralingam, M.]]  | ||
[[Category: SO4]]  | [[Category: SO4]]  | ||
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[[Category: muscle protein]]  | [[Category: muscle protein]]  | ||
| - | ''Page seeded by [http://  | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:04:49 2008''  | 
Revision as of 12:04, 21 February 2008
  | 
TROPONIN C
Overview
The crystal structures of three metal complexes of troponin C (TnC) have been determined and refined where the two occupied structural Ca(2+) sites in the C domain have been substituted by Mn(2+), Cd(2+) and Tb(3+). The X-ray intensity data were collected to 2.1, 1.8 and 1.8 A resolution, respectively, on the three metal complexes, which are isomorphous with Ca-TnC. The three complexes have r.m.s. deviations of 0.27, 0.25 and 0.35 A, respectively, for all protein atoms, from Ca-TnC. Irrespective of the charge on the metal (+2 or +3), the occupied sites 3 and 4 exhibit a distorted pentagonal bipyramidal coordination, like Ca-TnC, with seven ligands, six from the 12-residue binding loop and the seventh from a water molecule. Mn(2+) at site 4 seems to display a longer distance to one of the carboxyl bidentate ligands representing an intermediate coordination simulating the six-coordinate Mg(2+). The carboxyl O atoms of the bidentate Glu12 are displaced on the side of the equatorial plane passing through the remaining three ligands with one O atom closer to the plane (Delta of 0.11 to 0.76 A) than the other (Delta of 0.93 to 1.38 A). The two axial ligands are an aspartic carboxyl O atom and a water molecule. The metal is displaced (0.18 to 0.56 A) towards the water facing the water channel.
About this Structure
1NCZ is a Single protein structure of sequence from Gallus gallus with and as ligands. Full crystallographic information is available from OCA.
Reference
X-ray structures of Mn, Cd and Tb metal complexes of troponin C., Rao ST, Satyshur KA, Greaser ML, Sundaralingam M, Acta Crystallogr D Biol Crystallogr. 1996 Sep 1;52(Pt 5):916-22. PMID:15299599
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