FIGURE 6.

HDX of SsoMCM with 3′-tail DNA versus SsoMCM with 3′-tail/5′-tail forked DNA substrate. A, butterfly plot for SsoMCM and 3′-tail DNA (□, positive values) and SsoMCM and 3′-tail/5′-tail DNA (♢, negative values) relative fractional exchange versus peptide number. *, peptides with significant differences. B–E, deuterium incorporation during the H/D exchange period for four representative peptides, including one with no significant change (B) and three others (C–E) with significant differences between the two conditions (□, 3′-tail, pink; ♢, 3′-tail/5′-tail, green). Time course deuterium incorporation levels were generated by an MEM fitting method as described under “Experimental Procedures.” Peptide regions with significant deuterium uptake differences are mapped on the surface of SsoMCM, highlighting monomer (F), the interior channel (cutaway of top two subunits) (G), and the exterior surface (H). Error bars, S.E.