Sequence and structural comparison of monobodies L2 and L3. (A) Sequence alignment of L2 and L3. Sequences that varied during monobody selection are shown in red. Negatively charged residues in L3 near the channel binding interface are marked with asterisks. (B) Cartoon representation of L2 (yellow) and L3 homology model (blue) with residues that were varied during monobody selection represented as beads. Right, superposition of L2 and L3 homology model.