SNAP annotations: PDB entry 4e68

PDB-id

4e68; DSSR-derived features in text and JSON formats; DNAproDB

Class

transcription-DNA

Method

X-ray (2.585 Å)

Summary

Unphosphorylated stat3b core protein binding to dsDNA

Reference

Nkansah E, Shah R, Collie GW, Parkinson GN, Palmer J, Rahman KM, Bui TT, Drake AF, Husby J, Neidle S, Zinzalla G, Thurston DE, Wilderspin AF (2013): "Observation of unphosphorylated STAT3 core protein binding to target dsDNA by PEMSA and X-ray crystallography." Febs Lett., 587, 833-839. doi: 10.1016/j.febslet.2013.01.065.

Abstract

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.