Close-up view of the 2b-2c loops of KBTBD4-A (slate) and KBTBD4-B (green) after the β-propeller domain of the former is superimposed onto that of the latter. Side chains of two arginine residues in the 2b-2c loop of KBTBD4-B are shown in sticks. Left, KBTBD4-PR; right, KBTBD4-TTYML.
