Creatine kinase shapes up

摘要

WHEN you need a burst of energy, a crea-tine kinase (CK) will undoubtedly be involved. These are a family of distinct but related enzymes found in abundance in rapidly respiring tissues of vertebrates, including smooth and striated muscle, heart muscle, brain, sperm and mitochondria. In a landmark paper that appears on page 341 of this issue, Fritz-Wolf et al. report the very first CK crystal structure. It is of the octameric Mi_b, (for mitochondrial)-CK from chicken cardiac tissue, and reveals for the first time, some of the key structural features of the catalytic (active) site. This is a notable achievement because the structural solution of a CK had eluded several other crystallographic groups for many years.