Fig. 4. (a) Structure of WT Pa HasA (PDB ID: 3ELL), highlighting key residues in cyan: H32, Y75, and H83. (b) Normalised (280 nm) absorption spectra of HasA variants reconstituted with P-1: WT (
), H32C (
), H32S (
), V38C (
), and Y75F (
). (c) Emission spectra of absorbance-matched samples (A(520) = 0.0411 ± 0.0004) of HasA variants reconstituted with P-1: WT (
), H32C (
), H32S (
), V38C (
), and Y75F (
).
