Summary information and primary citation
- PDB-id
-
6sko;
DSSR-derived features in text and
JSON formats
- Class
- replication
- Method
- cryo-EM (3.4 Å)
- Summary
- cryo-EM structure of the fork protection complex bound
to cmg at a replication fork - conformation 2 mcm
ctd:ssDNA
- Reference
-
Baretic D, Jenkyn-Bedford M, Aria V, Cannone G, Skehel M,
Yeeles JTP (2020): "Cryo-EM
Structure of the Fork Protection Complex Bound to CMG at
a Replication Fork." Mol.Cell,
78, 926-940.e13. doi: 10.1016/j.molcel.2020.04.012.
- Abstract
- The eukaryotic replisome, organized around the
Cdc45-MCM-GINS (CMG) helicase, orchestrates chromosome
replication. Multiple factors associate directly with CMG,
including Ctf4 and the heterotrimeric fork protection
complex (Csm3/Tof1 and Mrc1), which has important roles
including aiding normal replication rates and stabilizing
stalled forks. How these proteins interface with CMG to
execute these functions is poorly understood. Here we
present 3 to 3.5 Å resolution electron cryomicroscopy
(cryo-EM) structures comprising CMG, Ctf4, and the fork
protection complex at a replication fork. The structures
provide high-resolution views of CMG-DNA interactions,
revealing a mechanism for strand separation, and show
Csm3/Tof1 "grip" duplex DNA ahead of CMG via a network of
interactions important for efficient replication fork
pausing. Although Mrc1 was not resolved in our structures,
we determine its topology in the replisome by cross-linking
mass spectrometry. Collectively, our work reveals how four
highly conserved replisome components collaborate with CMG
to facilitate replisome progression and maintain genome
stability.
