FIG. 2.
Recombinant TRIM5-21R proteins are monomers and dimers. Equilibrium sedimentation distributions of purified monomeric (A) and dimeric (B) TRIM5-21R proteins (upper panels), and residual differences between the data and the single species models (lower panels). The data are shown for initial subunit protein concentrations of 6.09, 3.05, and 1.53 μM (monomer), and 6.0, 3.0, and 1.5 μM (dimer) at rotor speeds of 14,000 rpm. The data sets were also collected at 18,000 rpm (monomer) and 16,000 (dimer), and all of the data were globally fit to a single species model in which the molecular weight was allowed to float during the refinement. The data points are shown in open symbols, and the best-fit curves are shown as solid lines. Estimated molecular weights were as follows: TRIM5-21R monomer, 59,305 g/mol (MWmonomer = 62,520 g/mol, Mobs/Mcalc = 0.95); and TRIM5-21R dimer, 123,825 g/mol (MWdimer = 125,040 g/mol, Mobs/Mmonomer = 1.98).