1qk1
From Proteopedia
(New page: 200px<br /> <applet load="1qk1" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qk1, resolution 2.70Å" /> '''CRYSTAL STRUCTURE O...) |
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| - | [[Image:1qk1.gif|left|200px]]<br /> | + | [[Image:1qk1.gif|left|200px]]<br /><applet load="1qk1" size="350" color="white" frame="true" align="right" spinBox="true" |
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caption="1qk1, resolution 2.70Å" /> | caption="1qk1, resolution 2.70Å" /> | ||
'''CRYSTAL STRUCTURE OF HUMAN UBIQUITOUS MITOCHONDRIAL CREATINE KINASE'''<br /> | '''CRYSTAL STRUCTURE OF HUMAN UBIQUITOUS MITOCHONDRIAL CREATINE KINASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Creatine kinase (CK), catalyzing the reversible trans-phosphorylation | + | Creatine kinase (CK), catalyzing the reversible trans-phosphorylation between ATP and creatine, plays a key role in the energy metabolism of cells with high and fluctuating energy requirements. We have solved the X-ray structure of octameric human ubiquitous mitochondrial CK (uMtCK) at 2.7 A resolution, representing the first human CK structure. The structure is very similar to the previously determined structure of sarcomeric mitochondrial CK (sMtCK). The cuboidal octamer has 422 point group symmetry with four dimers arranged along the fourfold axis and a central channel of approximately 20 A diameter, which extends through the whole octamer. Structural differences with respect to sMtCK are found in isoform-specific regions important for octamer formation and membrane binding. Octameric uMtCK is stabilized by numerous additional polar interactions between the N-termini of neighboring dimers, which extend into the central channel and form clamp-like structures, and by a pair of salt bridges in the hydrophobic interaction patch. The five C-terminal residues of uMtCK, carrying positive charges likely to be involved in phospholipid-binding, are poorly defined by electron density, indicating a more flexible region than the corresponding one in sMtCK. The structural differences between uMtCK and sMtCK are consistent with biochemical studies on octamer stability and membrane binding of the two isoforms. |
==About this Structure== | ==About this Structure== | ||
| - | 1QK1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with PO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Creatine_kinase Creatine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.3.2 2.7.3.2] Full crystallographic information is available from [http:// | + | 1QK1 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=PO4:'>PO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Creatine_kinase Creatine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.3.2 2.7.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QK1 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: octamer stability]] | [[Category: octamer stability]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:40:27 2008'' |
Revision as of 12:40, 21 February 2008
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CRYSTAL STRUCTURE OF HUMAN UBIQUITOUS MITOCHONDRIAL CREATINE KINASE
Overview
Creatine kinase (CK), catalyzing the reversible trans-phosphorylation between ATP and creatine, plays a key role in the energy metabolism of cells with high and fluctuating energy requirements. We have solved the X-ray structure of octameric human ubiquitous mitochondrial CK (uMtCK) at 2.7 A resolution, representing the first human CK structure. The structure is very similar to the previously determined structure of sarcomeric mitochondrial CK (sMtCK). The cuboidal octamer has 422 point group symmetry with four dimers arranged along the fourfold axis and a central channel of approximately 20 A diameter, which extends through the whole octamer. Structural differences with respect to sMtCK are found in isoform-specific regions important for octamer formation and membrane binding. Octameric uMtCK is stabilized by numerous additional polar interactions between the N-termini of neighboring dimers, which extend into the central channel and form clamp-like structures, and by a pair of salt bridges in the hydrophobic interaction patch. The five C-terminal residues of uMtCK, carrying positive charges likely to be involved in phospholipid-binding, are poorly defined by electron density, indicating a more flexible region than the corresponding one in sMtCK. The structural differences between uMtCK and sMtCK are consistent with biochemical studies on octamer stability and membrane binding of the two isoforms.
About this Structure
1QK1 is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Creatine kinase, with EC number 2.7.3.2 Full crystallographic information is available from OCA.
Reference
Crystal structure of human ubiquitous mitochondrial creatine kinase., Eder M, Fritz-Wolf K, Kabsch W, Wallimann T, Schlattner U, Proteins. 2000 May 15;39(3):216-25. PMID:10737943
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