FIG. 2.

Diffusion coefficients for GFP-tagged proteins in the E. coli DH5α cytoplasm. The mean diffusion coefficient ± SD is shown. “GFPn” represents multimers of torA-GFP from GFP1 to GFP5 (from left to right), as described in the text. The line shows the mean predicted D (± SD [gray-shaded area]) estimated by using the Einstein-Stokes equation to extrapolate from data for GFP1 (18) to larger proteins. Note that GFP multimers up to GFP4 show diffusion coefficients in line with this prediction. M, molecular mass.