PT  - JOURNAL ARTICLE
AU  - Sloan, Jeremy
AU  - Hakenjos, Jana P.
AU  - Gebert, Michael
AU  - Ermakova, Olga
AU  - Gumiero, Andrea
AU  - Stier, Gunter
AU  - Wild, Klemens
AU  - Sinning, Irmgard
AU  - Lohmann, Jan U.
TI  - Structural basis for the complex DNA binding behavior of the plant stem cell regulator WUSCHEL
AID  - 10.1101/2020.03.26.009761
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.03.26.009761
4099  - http://biorxiv.org/content/early/2020/03/30/2020.03.26.009761.short
4100  - http://biorxiv.org/content/early/2020/03/30/2020.03.26.009761.full
AB  - Stem cells are one of the foundational evolutionary novelties that allowed the independent emergence of multicellularity in the plant and animal lineages. In plants, the homeodomain (HD) transcription factor WUSCHEL (WUS) is essential for the maintenance of stem cells in the shoot apical meristem. WUS has been reported to bind to diverse DNA motifs and to act as transcriptional activator and repressor. However, the mechanisms underlying this remarkable behavior have remained unclear. Here, we quantitatively delineate WUS binding to three divergent DNA motifs and resolve the relevant structural underpinnings. We show that WUS exhibits a strong binding preference for TGAA repeat sequences, while retaining the ability to weakly bind to TAAT elements. This behavior is attributable the formation of dimers through interactions of specific residues in the HD that stabilize WUS DNA interaction. Our results provide a mechanistic basis for dissecting WUS dependent regulatory networks in plant stem cell control.