Wiley, FEBS Letters, 7(587), p. 833-839, 2013
DOI: 10.1016/j.febslet.2013.01.065
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The STAT3 transcription factor plays a central role in a wide range of cancer types where it is over-expressed. Previously, phosphorylation of this protein was thought to be a prerequisite for direct binding to DNA. However, we have now shown complete binding of a purified unphosphorylated STAT3 (uSTAT3) core directly to M67 DNA, the high affinity STAT3 target DNA sequence, by a protein electrophoretic mobility shift assay (PEMSA). Binding to M67 DNA was inhibited by addition of increasing concentrations of a phosphotyrosyl peptide. X-ray crystallography demonstrates one mode of binding that is similar to that known for the STAT3 core phosphorylated at Y705. STRUCTURED SUMMARY OF PROTEIN INTERACTIONS: pSTAT3βtcandpSTAT3βtcbindbymolecular sieving(View interaction).