Diffusion coefficients obtained by FCS measurements (Figure 2) and geometrical properties of MalE2 molecule (see Materials and Methods section for more details).

(1)Errors on FCS measurements.(2)Molecular radius (RSph calculated from the D1 diffusion coefficient using equation 3).(3)Prolate ellipsoid semi-axes (a, b) and corresponding diffusion coefficient (DE) calculated using Equation 4, assuming the same spherical volume obtained at pH 7.0 (i.e. 1·105 A3).