Structural basis for the autoinhibition of calcium/calmodulin-dependent protein kinase I.
The crystal structure of calcium/calmodulin-dependent protein kinase I has been determined in the autoinhibited form. The C-terminal regulatory region of the enzyme forms a helix-loop-helix segment that extends across the two domains of the catalytic core, making multiple inhibitory interactions. Elements of the first regulatory alpha helix and the loop interfere with the binding site for peptide substrates, while the loop and the second helix interact with the ATP-binding domain to induce conformational changes that obstruct the nucleotide binding pocket. One part of the calmodulin recognition element protrudes away from the catalytic domain and is potentially available for an initial interaction with calmodulin. The structure provides a view of an intact calmodulin target and suggests that substantial structural changes will accompany kinase activation by calmodulin binding to the regulatory region.
Goldberg
J
J
Howard Hughes Medical Institute, The Rockefeller University, New York, 10021, USA.
Nairn
A C
AC
Kuriyan
J
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites / Q000502:physiology; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D003461:Crystallography; D007091:Image Processing, Computer-Assisted; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011487:Protein Conformation; D011494:Protein Kinases / Q000737:chemistry / Q000648:ultrastructure; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D000255:Adenosine Triphosphate; D011494:Protein Kinases; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C517599:Camk1 protein, rat; C517682:Pnck protein, rat