1QK1

CRYSTAL STRUCTURE OF HUMAN UBIQUITOUS MITOCHONDRIAL CREATINE KINASE

Summary for 1QK1

• Entry DOI: 10.2210/pdb1qk1/pdb
• Related: 1CRK
• Descriptor: CREATINE KINASE, UBIQUITOUS MITOCHONDRIAL, PHOSPHATE ION (3 entities in total)
• Functional Keywords: transferase (creatine kinase), mitochondrial creatine kinase, cancer, cellular energy metabolism, guanidino kinase, mitochondrial permeability transition, octamer stability
• Biological source: HOMO SAPIENS (HUMAN)
• Total number of polymer chains: 8
• Total formula weight: 346488.46

Authors

Eder, M.,Schlattner, U.,Fritz-Wolf, K.,Wallimann, T.,Kabsch, W. (deposition date: 1999-07-08, release date: 2000-04-11, Last modification date: 2023-12-13)

Primary citation

Eder, M.,Fritz-Wolf, K.,Kabsch, W.,Wallimann, T.,Schlattner, U.
Crystal Structure of Human Ubiquitous Mitochondrial Creatine Kinase
Proteins: Struct.,Funct., Genet., 39:216-, 2000

PubMed Abstract: 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.

PubMed: 10737943
DOI: 10.1002/(SICI)1097-0134(20000515)39:3<216::AID-PROT40>3.0.CO;2-#

Experimental method

X-RAY DIFFRACTION (2.7 Å)