Copyright information:Taken from "Nuclease activity of the MutS homologue MutS2 from is confined to the Smr domain"Nucleic Acids Research 2007;35(3):850-860.Published online 10 Jan 2007PMCID:PMC1807967.© 2007 The Author(s) () The pH-dependent change of CD value at 222 nm. CD spectra of 2 μM ttMutS2 were analyzed under various pH conditions after incubation at 25°C for 24 h under each pH condition. CD values at 222 nm were plotted relative to pH. Triangles and circles are ttSmr and ttMutS2, respectively. () Substrate plasmid DNA was incubated without ttMutS2 under various pH conditions at 37°C for 120 min. () Substrate plasmid DNA was incubated with 200 nM ttMutS2 under various pH conditions at 37°C for 120 min. Reaction mixtures were subjected to 0.7% agarose gel electrophoresis and stained with ethidium bromide. Cont. represents substrate without incubation. () P-labeled 20 bp dsDNA (20 nM) was incubated with the indicated concentration of ttMutS2 at 37°C for 20 min under various pH conditions. Initial rates () were calculated on the basis of the proportion of all products to unreacted substrates and then plotted against the protein concentration. () values at each pH were determined by fitting the data in (C) to , and then plotted relative to pH. This plot was fitted to (see Materials and Methods), and the theoretical curve was drawn. Triangles and circles are ttSmr and ttMutS2, respectively.