title: Steric mechanism of auto-inhibitory regulation of specific and non-specific DNA binding by the ETS transcriptional repressor ETV6.
abstract: DNA binding by the ETS transcriptional repressor ETV6 (or TEL) is auto-inhibited ~50-fold due to an α-helix that sterically blocks its ETS domain binding interface. Using NMR spectroscopy, we demonstrate that this marginally stable helix is unfolded, and not displaced to a non-inhibitory position, when ETV6 is bound to DNA containing a consensus (5')GGAA(3') recognition site. Although significantly lower in affinity, binding to non-specific DNA is auto-inhibited ~5-fold and is also accompanied by helix unfolding. Based on NMR chemical shift perturbations, both specific and non-specific DNA are bound via the same canonical ETS domain interface. However, spectral perturbations are smaller for the non-specific complex, suggesting weaker and less well-defined interactions than in the specific complex. In parallel, the crystal structure of ETV6 bound to a specific DNA duplex was determined. The structure of this complex reveals that a non-conserved histidine residue in the ETS domain recognition helix helps establish the specificity of ETV6 for DNA-binding sites containing (5')GGAA(3')versus(5')GGAT(3'). These studies provide a unified steric mechanism for attenuating ETV6 binding to both specific and non-specific DNA and expand the repertoire of characterized auto-inhibitory strategies utilized to regulate ETS factors.
authors: Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors: Soumya
authors: S
authors: De
authors: Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors: Anson C K
authors: AC
authors: Chan
authors: Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors: H Jerome
authors: HJ
authors: Coyne
authors: Department of Oncological Sciences, University of Utah School of Medicine, and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112-5550, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA.
authors: Niraja
authors: N
authors: Bhachech
authors: Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors: Ulrike
authors: U
authors: Hermsdorf
authors: Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors: Mark
authors: M
authors: Okon
authors: Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors: Michael E P
authors: ME
authors: Murphy
authors: Department of Oncological Sciences, University of Utah School of Medicine, and Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112-5550, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815-6789, USA.
authors: Barbara J
authors: BJ
authors: Graves
authors: Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada V6T 1Z3. Electronic address: mcintosh@chem.ubc.ca.
authors: Lawrence P
authors: LP
authors: McIntosh
mesh_terms: D000818:Animals; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051379:Mice; D011485:Protein Binding; D017433:Protein Structure, Secondary; D050783:Proto-Oncogene Proteins c-ets / Q000737:chemistry* / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D004247:DNA; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein
keywords: ETS family; helix unfolding; inhibitory module; protein–DNA interface; winged helix–turn–helix