SNAP output for PDB entry 8foj [SNAP web server]

PDB-id

8foj; SNAP-derived features in text and JSON formats; DNAproDB

Class

DNA binding protein

Method

cryo-EM (4.8 Å)

Summary

cryo-EM structure of s. cerevisiae DNA polymerase alpha-primase complex in the post RNA handoff state

Reference

Yuan Z, Georgescu R, Li H, O'Donnell ME (2023): "Molecular choreography of primer synthesis by the eukaryotic Pol alpha-primase." Nat Commun, 14, 3697. doi: 10.1038/s41467-023-39441-1.

Abstract

The eukaryotic polymerase α (Pol α) synthesizes an RNA-DNA hybrid primer of 20-30 nucleotides. Pol α is composed of Pol1, Pol12, Primase 1 (Pri1), and Pri2. Pol1 and Pri1 contain the DNA polymerase and RNA primase activities, respectively. It has been unclear how Pol α hands over an RNA primer from Pri1 to Pol1 for DNA primer extension, and how the primer length is defined. Here we report the cryo-EM analysis of yeast Pol α in the apo, primer initiation, primer elongation, RNA primer hand-off from Pri1 to Pol1, and DNA extension states, revealing a series of very large movements. We reveal a critical point at which Pol1-core moves to take over the 3'-end of the RNA from Pri1. DNA extension is limited by a spiral motion of Pol1-core. Since both Pri1 and Pol1-core are flexibly attached to a stable platform, primer growth produces stress that limits the primer length.