Figure 4.

SspRNAP backtracks faster than EcRNAP for 1 bp, but not for long distances. (A) Kinetics of hydrolysis of RNA15 in the correct elongation complex (scheme above the gel) on template 2 by SspRNAP and EcRNAPs with rates of reaction underneath the gel calculated after fitting the data into exponential equation by SigmaPlot software. (B) Backtracking on T7A1 promoter template by SspRNAP and EcRNAP. Elongation complex EC27 prone to backtracking was formed and incubated at 37°C at pH 6.0 for the indicated periods of time to allow backtracking to happen. Remaining activity was assessed by the ability of complexes able to elongate RNA to position 30 after addition of 1 mM CTP.