Quercetin binds to calcineurin at a similar region to cyclosporin A and tacrolimus

► We found quercetin bound to calcineurin (CN) to show its strong inhibition effect. ► Three potential binding sites for quercetin were indicated locating at the junction of CNA and CNB. ► This location was the same binding area for cyclosporin A and tacrolimus on CN. ► This region is also important for CN substrate recognition.