DNA polymerase D temporarily connects primase to the CMG-like helicase before interacting with proliferating cell nuclear antigen.
Nucleic Acids Res
; 49(8): 4599-4612, 2021 05 07.
Article
en En
| MEDLINE
| ID: mdl-33849056
ABSTRACT
The eukaryotic replisome is comprised of three family-B DNA polymerases (Polα, δ and ϵ). Polα forms a stable complex with primase to synthesize short RNA-DNA primers, which are subsequently elongated by Polδ and Polϵ in concert with proliferating cell nuclear antigen (PCNA). In some species of archaea, family-D DNA polymerase (PolD) is the only DNA polymerase essential for cell viability, raising the question of how it alone conducts the bulk of DNA synthesis. We used a hyperthermophilic archaeon, Thermococcus kodakarensis, to demonstrate that PolD connects primase to the archaeal replisome before interacting with PCNA. Whereas PolD stably connects primase to GINS, a component of CMG helicase, cryo-EM analysis indicated a highly flexible PolD-primase complex. A conserved hydrophobic motif at the C-terminus of the DP2 subunit of PolD, a PIP (PCNA-Interacting Peptide) motif, was critical for the interaction with primase. The dissociation of primase was induced by DNA-dependent binding of PCNA to PolD. Point mutations in the alternative PIP-motif of DP2 abrogated the molecular switching that converts the archaeal replicase from de novo to processive synthesis mode.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
ADN Helicasas
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Antígeno Nuclear de Célula en Proliferación
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Thermococcus
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ADN Primasa
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Proteínas Arqueales
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ADN Polimerasa III
Idioma:
En
Año:
2021
Tipo del documento:
Article