Fig. 2: dCMGE formation reconfigures the double hexamer interface, resulting in a splayed dimer.
From: Mechanism of replication origin melting nucleated by CMG helicase assembly
a, Surface rendering of the dCMGE complex. b, Double-hexamer-to-dCMGE conversion promotes a one-subunit register shift at the MCM dimerization interface. Circles represent ZnFs. Black circles connected by lines indicate ZnFs engaged in tight inter-ring interactions. c, Double-hexamer-to-dCMGE conversion promotes the disengagement of an Mcm7 α-helical extension that protects the Mcm5 A domain on the opposite ring. This structural change exposes a GINS-binding site on Mcm5. PDB 7P30 refers to the Protein Data Bank (PDB) accession code. d, The dCMGE dimer is held together by a Mcm6 homo-dimer as well as by the DNA duplex. The dCMGE splayed dimer exposes a stretch of twisted duplex DNA that intervenes between the two MCM rings. e, DNA digestion disrupts the dCMGE dimer into single isolated CMGs (sCMGs), while also promoting the disengagement of Pol ε. This experiment was performed twice. Mean values are shown.
