Conserved interactions between the RBD and CDRs of class 2 NAbs as observed for a-d, C144 (HC: cyan, LC: sky blue), e-h, C002 (HC: dark orange, LC: light orange), and i-l, C121 (HC: purple, LC: pink). Primary and secondary epitopes on adjacent “down” RBDs are shown for C144. Secondary epitopes for C002 and C121, which require adjacent “up” RBDs, are shown in Extended Data Fig.5. RBDs are gray; potential H-bonds and pi-pi stacking interactions (panel d, Y33LC and F486RBD; panel h, Y92LC and F486RBD; panel l, Y91LC and F486RBD) are indicated by dashed lines.