Fig. 7

Homology models of DDK sequences. Models are shown in ribbon representation with the residues that influence the active site cavity shown in stick representation. Cavities are depicted as a transparent surface. Oxygen, nitrogen and sulphur atoms are coloured red, blue and yellow respectively. a The crystal structure of A. thaliana KAI2 in complex with karrikin (KAR ₁ ) is shown in navy blue (PDB code 4JYM). Residue numbers correspond to the unified numbering scheme as in Fig. 5; they are –1 relative to those of A. thaliana KAI2. b The crystal structure of A. thaliana D14 is shown in red. c, d Lycophyte DDK homology models are shown in olive green; c Selaginella moellendorffii (previously referred to as KAI2b), d Lycopodium annotinum. e–h Monilophyte DDK homology models are shown in lime green; e Osmunda sp. DDKb, f Polypodium amorphum DDKA, g Cystopteris fragilis DDKA, h Asplenium platyneuron DDKB