title: Three-dimensional structure and regulation of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs).
abstract: DNA-PKcs is a large PI3-kinase-related protein kinase (PIKK) that plays a central role in DNA double-strand break (DSB) repair via nonhomologous end joining. Using cryo-electron microscopy we have now generated an approximately 13 A three-dimensional map of DNA-PKcs, revealing the overall architecture and topology of the 4128 residue polypeptide chain and allowing location of domains. The highly conserved C-terminal PIKK catalytic domain forms a central structure from which FAT and FATC domains protrude. Conformational changes observed in these domains on DNA binding suggest that they transduce DNA-induced conformational changes to the catalytic core and regulate kinase activity. The N-terminal segments form long curved tubular-shaped domains based on helical repeats to create interacting surfaces required for macromolecular assembly. Comparison of DNA-PKcs with another PIKK DNA repair factor, ATM, defines a common architecture for this important protein family.
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, Campus Universidad Complutense, 28040 Madrid, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: Rivera-Calzada
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Maman
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Maman
authors.forename: Laura
authors.initials: L
authors.lastname: Spagnolo
authors.forename: Laurence H
authors.initials: LH
authors.lastname: Pearl
authors.forename: Oscar
authors.initials: O
authors.lastname: Llorca
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins; D020134:Catalytic Domain; D018797:Cell Cycle Proteins / Q000737:chemistry; D020285:Cryoelectron Microscopy; D004247:DNA / Q000378:metabolism; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004789:Enzyme Activation; D006801:Humans; D008968:Molecular Conformation; D009687:Nuclear Proteins; D019869:Phosphatidylinositol 3-Kinases / Q000737:chemistry; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D025521:Tumor Suppressor Proteins / Q000737:chemistry
chemical_list: D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins; D004247:DNA; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D025521:Tumor Suppressor Proteins; C576324:ATM protein, human; C497263:PRKDC protein, human