Fig. 5: Model for DNA unwinding in a steric exclusion CMG helicase derived from this study.
From: DNA unwinding mechanism of a eukaryotic replicative CMG helicase
OB Hp loops in the NTDs of Mcms7, 4 and 6 form a block, or dam for incoming 5’ tailed DNA, and the OB Hp loop in the NTD of Mcm3 forms the top of a diversion tunnel, or channel for the displaced lagging 5’ strand that travels between the zinc fingers of Mcm3 and 5 at the N-tier surface of CMG. The PS1 and H2I loops in the C-tier motor domain pull the DNA through the diversion tunnel in the N-tier for the steric exclusion process of DNA unwinding. See text for details.
