Fig. 2.

Structural analysis of ARR1^RD-DBD. (A) The overall structure of ARR1^RD-DBD is outlined by ribbon cartoon. The RD and DBD of ARR1^RD-DBD are in blue and green, respectively. (B) Zoomed-in view of the intermolecular interactions between the RD (blue) and DBD (green) of ARR1^RD-DBD. The interacting residues are identified in stick representations, with hydrogen bonding interactions shown by dashed lines. (C) Topology of the RD of ARR1^RD-DBD. Structural elements are labeled. (D) SDS-PAGE illustrating the effects of the mutations on interface formation between the RD and DBD determined through in vitro pull-down experiments. Wild-type (WT) and mutated versions of ARR1^RD and ARR1^DBD were fused to glutathione S-transferase (GST) and 6xHis, respectively. (E) Sequence alignment of B-ARRs from Arabidopsis. Accession numbers are ARR1 (NP_850600.2), ARR2 (NP_193346.5), ARR10 (NP_194920.1), ARR11 (NP_176938.1), ARR12 (NP_180090.6), ARR14 (NP_001324402.1), and ARR18 (NP_200616.4). The conserved amino acids on the interface (B) are outlined by black triangles. (F) Phylogenetic tree of ARRs in Arabidopsis. The A-ARRs and B-ARRs are highlighted in red and blue shading, respectively.