pfam08163: DNAPKcs_CC3 (This model is not part of the current CDD release)
DNA-dependent protein kinase catalytic subunit, CC3
DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is involved in DNA nonhomologous end joining (NHEJ), which is recruited by Ku70/80 heterodimer to DNA ends and required for double-strand breaks (DSBs) repair. DNA-PKcs phosphorylates a number of protein substrates, including the heat shock protein 90 (HSP90), the transcription factors p53, specificity protein 1 (Sp1), among others. It folds into three well-defined large structural units, consisting of a N-terminal region (arranged in four supersecondary alpha-helical structures, N1-N4), the Circular Cradle (consisting of five supersecondary alpha-helical structures CC1-CC5), and the C-terminal Head (comprising FAT, FRB, kinase, and FATC). The CCs form a curved elliptical ring that serves as a scaffold to maintain the integrity of the whole complex. This domain represents a region of the Circular Cradle segment (CC) from DNA-PKcs that covers the complete CC3 and part of CC4. This domain contains the Ku-binding site A and a the highly conserved region (HCR) II.
Jiyao W et al.(2023). "The conserved domain database in 2023.",