Fig. 2: Conformational dynamics of the dimeric CRL3^KLHL22 generate a variable ubiquitination zone.

a Local resolution map of CRL3^KLHL22. The resolution decreased from the dimer assembly region (blue dashed line) to the ubiquitination region (red dashed line). b Overlay of cryo-EM density maps with compact (Frame 1, purple) and relaxed (Frame 20, pink) conformations of CRL3^KLHL22. The dynamics of the CUL3 three helix-bundle repeats domain (CR1, CR2, and CR3) contribute to the conformational change. c–e CRL3^KLHL22 undergoes conformational changes from a compact conformation to a relaxed conformation. The long-axis distance increased from 215 Å to 225 Å (c). The angle between KLHL22 and CUL3 scaffold subunit increased from 20° to 30° (d). The distance between two RBX1 subunits increased from 105 Å to 135 Å (e). f Shown is a cartoon model of CRL3^KLHL22 conformational changes. The dynamic of the CUL3 scaffold subunit leads CRL3^KLHL22 to transition between a compact conformation and a relaxed conformation, which generates a variable ubiquitination zone.