A SAM oligomerization domain shapes the genomic binding landscape of the LEAFY transcription factor

Nat Commun. 2016 Apr 21;7:11222. doi: 10.1038/ncomms11222.

Abstract

Deciphering the mechanisms directing transcription factors (TFs) to specific genome regions is essential to understand and predict transcriptional regulation. TFs recognize short DNA motifs primarily through their DNA-binding domain. Some TFs also possess an oligomerization domain suspected to potentiate DNA binding but for which the genome-wide influence remains poorly understood. Here we focus on the LEAFY transcription factor, a master regulator of flower development in angiosperms. We have determined the crystal structure of its conserved amino-terminal domain, revealing an unanticipated Sterile Alpha Motif oligomerization domain. We show that this domain is essential to LEAFY floral function. Moreover, combined biochemical and genome-wide assays suggest that oligomerization is required for LEAFY to access regions with low-affinity binding sites or closed chromatin. This finding shows that domains that do not directly contact DNA can nevertheless have a profound impact on the DNA binding landscape of a TF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Binding Sites
  • Chromatin / chemistry
  • Chromatin / metabolism
  • Cloning, Molecular
  • Crystallography, X-Ray
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Flowers / genetics*
  • Flowers / growth & development
  • Flowers / metabolism
  • Gene Expression
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant*
  • Genome, Plant*
  • Models, Molecular
  • Molecular Sequence Data
  • Oryza / genetics*
  • Oryza / growth & development
  • Oryza / metabolism
  • Protein Binding
  • Protein Multimerization
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Transcription Factors / chemistry*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription, Genetic

Substances

  • Arabidopsis Proteins
  • Chromatin
  • LFY protein, Arabidopsis
  • Recombinant Proteins
  • Transcription Factors