PROTEIN-KINASES

The structures of four serine/threonine protein kinases have been dete rmined recently. By comparing these structures with that of the cAMP-d ependent protein kinase (cAPK), it is now possible to see how the acti vity of these regulatory enzymes is controlled. Low activity is mainta ined through the conformation of the phosphorylation lip, domain rotat ions, and binding of substrate analog inhibitors and autoinhibitory do mains.