Molecular and structural basis of target recognition by calmodulin.
Calmodulin (CaM) acts as an intracellular calcium sensor that translates the Ca2+ signal into a variety of cellular processes. Ca(2+)-CaM recognition of a short polypeptide segment in target proteins induces conformational changes in both CaM and the target, enabling the target protein to become functionally active. The solution and crystal structures of Ca(2+)-CaM bound to peptides derived from three CaM-dependent enzymes reveal structural features that are common in target recognition by Ca(2+)-CaM. Phosphorylation of the target proteins at sites in or near the CaM-binding region modulates binding of CaM, thereby providing an additional mechanism of functional regulation. The structural aspects of target recognition by Ca(2+)-CaM are discussed using mainly the three-dimensional structural information obtained with nuclear magnetic resonance spectroscopy and X-ray diffraction methods.
Crivici
A
A
Division of Molecular and Structural Biology, Ontario Cancer Institute, Toronto, Canada.
Ikura
M
M
D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000096:biosynthesis / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction / Q000502:physiology*
D002147:Calmodulin; D002118:Calcium