Fig. 5. The distributions of positions of Escherichia coli and Thermus aquaticus (Taq) MutS on different DNA substrates. The histograms are truncated at 50% because the ratios of shorter DNA arm to the total DNA length were measured. (a) The distribution of positions of E. coli MutS on 783GT DNA (n = 352) is Gaussian centered at 27 ± 6%. (b) The distribution of positions of Taq MutS on 783TBulge DNA (n = 429) is Gaussian centered at 25 ± 5%. (c) The distribution of positions of E. coli MutS on 982GT heteroduplex DNA substrate (n = 89) is also Gaussian centered at 44 ± 5%. (d) The distribution of E. coli MutS on a full homoduplex DNA, 782Homo DNA (n = 82) is random.