8G9L
DNA initiation subcomplex of Xenopus laevis DNA polymerase alpha-primase
Summary for 8G9L
| Entry DOI | 10.2210/pdb8g9l/pdb |
| EMDB information | 29862 29864 29871 29872 29873 29886 29888 29889 29891 |
| Descriptor | DNA polymerase alpha catalytic subunit, DNA primase large subunit, DNA template, ... (7 entities in total) |
| Functional Keywords | primase, dna polymerase, chimeric rna-dna primer, rna/dna hybrid, dna replication, dna synthesis, replication, transferase-dna-rna complex, transferase/dna/rna |
| Biological source | Xenopus laevis (African clawed frog) More |
| Total number of polymer chains | 4 |
| Total formula weight | 208049.33 |
| Authors | Mullins, E.A.,Durie, C.L.,Ohi, M.D.,Chazin, W.J.,Eichman, B.F. (deposition date: 2023-02-21, release date: 2023-04-12, Last modification date: 2024-05-29) |
| Primary citation | Mullins, E.A.,Salay, L.E.,Durie, C.L.,Bradley, N.P.,Jackman, J.E.,Ohi, M.D.,Chazin, W.J.,Eichman, B.F. A mechanistic model of primer synthesis from catalytic structures of DNA polymerase alpha-primase. Nat.Struct.Mol.Biol., 31:777-790, 2024 Cited by PubMed Abstract: The mechanism by which polymerase α-primase (polα-primase) synthesizes chimeric RNA-DNA primers of defined length and composition, necessary for replication fidelity and genome stability, is unknown. Here, we report cryo-EM structures of Xenopus laevis polα-primase in complex with primed templates representing various stages of DNA synthesis. Our data show how interaction of the primase regulatory subunit with the primer 5' end facilitates handoff of the primer to polα and increases polα processivity, thereby regulating both RNA and DNA composition. The structures detail how flexibility within the heterotetramer enables synthesis across two active sites and provide evidence that termination of DNA synthesis is facilitated by reduction of polα and primase affinities for the varied conformations along the chimeric primer-template duplex. Together, these findings elucidate a critical catalytic step in replication initiation and provide a comprehensive model for primer synthesis by polα-primase. PubMed: 38491139DOI: 10.1038/s41594-024-01227-4 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.3 Å) |
Structure validation
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