Cooperative Gsx2-DNA binding requires DNA bending and a novel Gsx2 homeodomain interface.

Autor:	Webb JA; Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA., Farrow E; Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA.; Medical-Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA., Cain B; Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 7007, Cincinnati, OH 45229, USA., Yuan Z; Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA., Yarawsky AE; Division of Immunobiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA., Schoch E; Department of Medical Education, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA., Gagliani EK; Department of Chemistry, Xavier University, Cincinnati, OH 45207, USA., Herr AB; Division of Immunobiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA., Gebelein B; Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 7007, Cincinnati, OH 45229, USA.; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA., Kovall RA; Department of Molecular and Cellular Biosciences, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
Jazyk:	angličtina
Zdroj:	Nucleic acids research [Nucleic Acids Res] 2024 Jul 22; Vol. 52 (13), pp. 7987-8002.
DOI:	10.1093/nar/gkae522
Abstrakt:	The conserved Gsx homeodomain (HD) transcription factors specify neural cell fates in animals from flies to mammals. Like many HD proteins, Gsx factors bind A/T-rich DNA sequences prompting the following question: How do HD factors that bind similar DNA sequences in vitro regulate specific target genes in vivo? Prior studies revealed that Gsx factors bind DNA both as a monomer on individual A/T-rich sites and as a cooperative homodimer to two sites spaced precisely 7 bp apart. However, the mechanistic basis for Gsx-DNA binding and cooperativity is poorly understood. Here, we used biochemical, biophysical, structural and modeling approaches to (i) show that Gsx factors are monomers in solution and require DNA for cooperative complex formation, (ii) define the affinity and thermodynamic binding parameters of Gsx2/DNA interactions, (iii) solve a high-resolution monomer/DNA structure that reveals that Gsx2 induces a 20° bend in DNA, (iv) identify a Gsx2 protein-protein interface required for cooperative DNA binding and (v) determine that flexible spacer DNA sequences enhance Gsx2 cooperativity on dimer sites. Altogether, our results provide a mechanistic basis for understanding the protein and DNA structural determinants that underlie cooperative DNA binding by Gsx factors. (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)
Databáze:	MEDLINE
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