Table 1. Native mass spectrometry of (apo)flavodoxin.

Species	Label in Figure 6	Expected mass (Da)	Measured mass (Da)	Δ(mass) (Da)
Apoflavodoxin	M	19531.8	19538±3	+6.2 Da
Flavodoxin	MH	19987.1	19995±3	+7.9 Da

Monomeric protein species are labelled M, Molecular masses of FMN is 455.3 Da. Expected mass and measured mass are average masses.