title: Mechanism of Concerted RNA-DNA Primer Synthesis by the Human Primosome.
abstract: The human primosome, a 340-kilodalton complex of primase and DNA polymerase α (Polα), synthesizes chimeric RNA-DNA primers to be extended by replicative DNA polymerases δ and ϵ. The intricate mechanism of concerted primer synthesis by two catalytic centers was an enigma for over three decades. Here we report the crystal structures of two key complexes, the human primosome and the C-terminal domain of the primase large subunit (p58C) with bound DNA/RNA duplex. These structures, along with analysis of primase/polymerase activities, provide a plausible mechanism for all transactions of the primosome including initiation, elongation, accurate counting of RNA primer length, primer transfer to Polα, and concerted autoregulation of alternate activation/inhibition of the catalytic centers. Our findings reveal a central role of p58C in the coordinated actions of two catalytic domains in the primosome and ultimately could impact the design of anticancer drugs.
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and.
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Baranovskiy
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and.
authors.forename: Nigar D
authors.initials: ND
authors.lastname: Babayeva
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and the Departments of Biochemistry and Molecular Biology and.
authors.forename: Yinbo
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and.
authors.forename: Jianyou
authors.initials: J
authors.lastname: Gu
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Suwa
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and the Departments of Biochemistry and Molecular Biology and Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198.
authors.forename: Youri I
authors.initials: YI
authors.lastname: Pavlov
authors.affiliation: From the Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center and ttahirov@unmc.edu.
authors.forename: Tahir H
authors.initials: TH
authors.lastname: Tahirov
mesh_terms: D004247:DNA / Q000096:biosynthesis / Q000737:chemistry*; D004256:DNA Polymerase I / Q000737:chemistry* / Q000378:metabolism; D019915:DNA Primase / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry* / Q000378:metabolism
chemical_list: D009097:Multienzyme Complexes; D009692:Nucleic Acid Heteroduplexes; D004247:DNA; D019915:DNA Primase; D004256:DNA Polymerase I
keywords: 5′-triphosphate; DNA polymerase; DNA primase; DNA-protein interaction; DNA/RNA duplex; RNA primer length counting; RNA synthesis; human DNA replication; initiating NTP; x-ray crystallography