title: Mechanism of replication machinery assembly as revealed by the DNA ligase-PCNA-DNA complex architecture.
abstract: The 3D structure of the ternary complex, consisting of DNA ligase, the proliferating cell nuclear antigen (PCNA) clamp, and DNA, was investigated by single-particle analysis. This report presents the structural view, where the crescent-shaped DNA ligase with 3 distinct domains surrounds the central DNA duplex, encircled by the closed PCNA ring, thus forming a double-layer structure with dual contacts between the 2 proteins. The relative orientations of the DNA ligase domains, which remarkably differ from those of the known crystal structures, suggest that a large domain rearrangement occurs upon ternary complex formation. A second contact was found between the PCNA ring and the middle adenylation domain of the DNA ligase. Notably, the map revealed a substantial DNA tilt from the PCNA ring axis. This structure allows us to propose a switching mechanism for the replication factors operating on the PCNA ring.
authors.affiliation: Medical Institute of Bioregulation, Kyushu University, and Institute for Bioinformatics Research and Development, Japan Science and Technology Agency, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka 812-8582, Japan. maya@bioreg.kyushu-u.ac.jp
authors.forename: Kouta
authors.initials: K
authors.lastname: Mayanagi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kiyonari
authors.forename: Mihoko
authors.initials: M
authors.lastname: Saito
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Shirai
authors.forename: Yoshizumi
authors.initials: Y
authors.lastname: Ishino
authors.forename: Kosuke
authors.initials: K
authors.lastname: Morikawa
mesh_terms: D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000737:chemistry* / Q000648:ultrastructure; D004261:DNA Replication; D008854:Microscopy, Electron; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry* / Q000648:ultrastructure; D020027:Pyrococcus furiosus / Q000201:enzymology*; D055672:Static Electricity
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D004247:DNA; D011088:DNA Ligases; D000072481:DNA Ligase ATP