(A) The dimeric W196A mutant crystal structure lacks C-loop density.
FAD domain (gold), NADH domain (green), C-terminal domain (teal),
β-hairpin and C-loop boundaries (red). See also Figure S4, Table S1.
(B) W196A FAD isoalloxazine ring (left) and NADH binding pocket
(right) (color) overlaid with structures of wild-type monomer (light gray, PDB:
4BV6) and dimer (dark gray, PDB: 4BUR).
(C) W196A C-terminal aromatic tunnel (left) and the border region of
the C-loop insertion (right) (color) overlaid with structures of wild-type
monomer (light gray) and dimer (dark gray).