Fig. 2: Co-crystal structures of FLN in complex with two hemoglobin peptide substrates.
A FLN in complex with the hemoglobin α-peptide. Residues K40 to P44 could be built with confidence and are displayed as sticks colored in orange. B FLN in complex with the hemoglobin β-peptide. Residues T38 to E43 are colored in purple. Overlayed are Fo–Fc electron density difference Fourier maps where the peptides were omitted from calculation, displayed as mesh, and contoured at 2σ level above the mean. The zinc ion is shown as a gray sphere, and zinc-coordinating residues as cyan sticks. The N-terminus and C-terminus of FLN are labeled in bold. The N-terminal half of FLN is colored in cyan, its C-terminal half in green; linker connecting the two halves is blue. C magnified views of the α- and β-peptides with the “omit” electron density maps calculated as in panels (A) and (B). D Superposition of FLN-MK-4815 complex structure (PDB accession code: 7DIJ) with the FLN-α- and β-peptide complex structures. Distances between the drug and each peptide are indicated. MK-4815 is depicted as gray sticks. E Display of FLN electrostatics molecular surface for its N-half and C-half. Peptide substrate from hemoglobin α chain and MK-4815 are shown as sticks and zinc ion as a gray sphere.
