A SAM oligomerization domain shapes the genomic binding landscape of the LEAFY transcription factor Academic Article uri icon


  • 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.


  • Sayou, Camille
  • Nanao, Max H
  • Jamin, Marc
  • Posé, David
  • Thévenon, Emmanuel
  • Grégoire, Laura
  • Tichtinsky, Gabrielle
  • Denay, Grégoire
  • Ott, Felix
  • Peirats-Llobet, Marta
  • Schmid, Markus
  • Dumas, Renaud
  • Parcy, François

publication date

  • 2016

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