1qk1
From Proteopedia
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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 PO4 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
Page seeded by OCA on Mon Nov 12 18:53:55 2007
