Crystallographic studies of casein kinase I δ: toward a structural understanding of auto-inhibition (original) (raw)

A recombinant form of mammalian casein kinase I δ (CKIδ) containing the catalytic domain and an auto-inhibitory domain was expressed in Escherichia coli, purified and crystallized. X-ray data were collected to 2.4 Å resolution, and the crystals belong to space group _C_2221. Molecular replacement using the structure of the catalytic domain of CKIδ yielded strong electron density for residues in the model, but no interpretable density was found for the inhibitory domain. A conserved intermolecular contact suggests the formation of dimers which would inhibit the activity of this protein kinase.