Figure 3.

An array was used to profile the activity of Taq DNA ligase against a panel of ternary substrates representing each possible base pair at the nick site. (A) Mass spectra reveal the extent to which the P2 probe strand was adenylated and the extent to which the two probe strands were joined. (B) The intensities of the peaks for the P2 probe strand (P2), the adenylated intermediate (I) and the ligated product (P) were used to profile the reaction. The first plot shows the yield for adenylation {(I + P)/(S + I + P)}; the second plot shows the yield for the relative activity for nick closure {P/(I + P)}; and the third plot shows the yield of ligated product {P/(S + I + P)}. The dotted blue and red lines indicate adenylated and ligated product, respectively. In the base pair notation X:Y, X refers to the target nucleotide and Y is the probe nucleotide.