FIGURE 2.

NMR analysis of p62 UBA dimerization. A, ¹H-¹⁵N HSQC spectra of ¹⁵N-labeled WT p62 UBA measured at high (200 μm) and low (3.1 μm) concentrations. B, one dimensional projections of spectral region I in A generated from the ¹H-¹⁵N HSQC spectra of ¹⁵N-labeled WT p62 UBA at various concentrations. The dissociation constant of the p62 UBA dimer was calculated from the populations of monomer and dimer species of the p62 UBA domain at each concentration based on the volume of Trp⁴¹⁴ H_ϵ1-N_ϵ1 side chain peaks of monomer and dimer. C, spectral subregion II in A is magnified, and the same regions of the spectra of various mutants are indicated. All mutants except I433V showed the characteristic monomer cross-peak pattern. I433V maintains the characteristic dimer cross-peak pattern.