Fig. 2
From: In vivo dynamics and regulation of DNA G-quadruplex structures in mammals
Cellular factors affecting eG4 dynamics. A During DNA replication, DNA helicase (blue ring) breaks the Watson–Crick hydrogen bond, resulting in the folding of DNA eG4s in S phase. B During transcription, RNA polymerase breaks the Watson–Crick hydrogen bond between the template chain and the non-template chain. When the DNA template chain and RNA form a heterozygous double strand, eG4 folding is induced on the non-template chain. C The nucleosome may prevent the Watson–Crick hydrogen bond from being broken, so that PQS cannot fold (orange), and the nucleosome depletion region is more conducive to eG4 folding