The transcription factor FraJ binds a poly-A DNA sequence with a


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The transcription factor FraJ binds a poly-A DNA sequence with a 10nM KD and a poly-G DNA sequence with a 27 μM KD. Mutation of a critical Phe residue to Ala result in a loss of 20 kJ * mol-1 in binding free energy for the poly-A sequence, but only a loss of 4 kJ * mol-1 on binding to the poly-G sequence. What is the change in specificity for the poly-A sequence over the poly-G sequence at 10-8 M concentration of FraJ at 300 K? Please show all of your work, thank you.

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