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-Structure paper
Title | cryo-EM structures of the replicative DNA polymerase reveal its dynamic interactions with the DNA sliding clamp, exonuclease and . |
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Journal, issue, pages | Elife, Vol. 4, Year 2015 |
Publish date | Oct 24, 2015 |
Authors | Rafael Fernandez-Leiro / Julian Conrad / Sjors Hw Scheres / Meindert H Lamers / |
PubMed Abstract | The replicative DNA polymerase PolIIIα from is a uniquely fast and processive enzyme. For its activity it relies on the DNA sliding clamp β, the proofreading exonuclease ε and the C-terminal ...The replicative DNA polymerase PolIIIα from is a uniquely fast and processive enzyme. For its activity it relies on the DNA sliding clamp β, the proofreading exonuclease ε and the C-terminal domain of the clamp loader subunit τ. Due to the dynamic nature of the four-protein complex it has long been refractory to structural characterization. Here we present the 8 Å resolution cryo-electron microscopy structures of DNA-bound and DNA-free states of the PolIII-clamp-exonuclease-τ complex. The structures show how the polymerase is tethered to the DNA through multiple contacts with the clamp and exonuclease. A novel contact between the polymerase and clamp is made in the DNA bound state, facilitated by a large movement of the polymerase tail domain and τ. These structures provide crucial insights into the organization of the catalytic core of the replisome and form an important step towards determining the structure of the complete holoenzyme. |
External links | Elife / PubMed:26499492 / PubMed Central |
Methods | EM (single particle) |
Resolution | 7.3 - 8.34 Å |
Structure data | EMDB-3198: Cryo-EM structure of the E. coli replicative DNA polymerase complex bound to DNA (DNA polymerase III alpha, beta, epsilon, and tau subunits) EMDB-3201: Cryo-EM structure of the E. coli replicative DNA polymerase complex in DNA free state (DNA polymerase III alpha, beta, epsilon, and tau subunits) EMDB-3202: Cryo-EM structure of the E. coli replicative DNA polymerase complex bound to DNA (DNA polymerase III alpha, beta, and epsilon subunits) |
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Keywords | TRANSFERASE / DNA REPLICATION / DNA POLYMERASE III ALPHA / DNA POLYMERASE III BETA / DNA POLYMERASE III EPSILON / DNA POLYMERASE III TAU |