G4 and R-loop signals at the indicated genomic locus. Both G4s and R-loops accumulate in cells where the resolution of G4 knots is defective (red). Not all DNA looks like the familiar twisted ladder.

Not all DNA looks like the familiar double helix. Sometimes, parts of our genetic code fold into unusual shapes under certain conditions. One such structure known as a G-quadruplex (G4) looks like a ...