Table 5.

Comparison of rate constants for mtSSB and EcoSSB

Rate constants are listed for DNA binding and release for short ssDNA (dT₃₀ for mtSSB and dT₃₅ for EcoSSB) and for full-length ssDNA (dT₆₀ for mtSSB and dT₇₀ for EcoSSB) and for the DNA concentration dependence of the DNA exchange reaction. Rate constants are numbered as in Schemes 1 and 2. The net DNA dissociation rate, k_−1,app, is calculated from Equation 2. The apparent second order rate constant for DNA exchange, k_3,app, is calculated from Equations 3 and 4. Rate constants for EcoSSB are from Refs. 20 and 32, measured in 0.2 m NaCl, pH 8.1, at 25°C. Rate constants for mtSSB from this report were determined in 0.1 m NaCl, 10 mm Mg²⁺, pH 7.5, at 37°C.

^a Estimated from the 200-fold reduction in binding affinity for the second binding.