FIGURE 4.
SAXS of MutSα, MutSαΔ341, and PCNA. A, scattering intensities versus Q are shown for MutSα (blue line), MutSαΔ12 (green line), MutSαΔ341 (red line), MutSαΔ341 complexed to a 15-bp G-T heteroduplex (brown line), and PCNA (black line). Linear portions of Guinier plots (inset) determined from scattering profiles were used to determine Rg values (shown in Table 1). B, normalized pairwise interatomic distances (P(r)) were derived from solution scattering intensities (see “Experimental Procedures”). The color scheme is as described for A. C, ab initio shape reconstructions of MutSαΔ341, MutSαΔ341 bound to a 15-bp G-T heteroduplex, and PCNA were obtained from SAXS data (see “Experimental Procedures”). SUPCOMB (28) was used to superimpose and align the crystal structure of PCNA (39) or the MutSαΔ341·DNA complex (14) on SAXS envelopes.