Figure 1.

Domain structure of Arabidopsis AIR9 and protozoan AIR9-like proteins and phylogenetic position of AIR9-like proteins in the tree of life. (A) All AIR9-like proteins contain an LRR domain and a region of repeated A9 domains. Arabidopsis AIR9 additionally shows an N-terminal serine-rich basic region that confers microtubule binding (MT) and a C-terminal conserved region of unknown function (cc). The multicopy genome of Trichomonas harbours several genes potentially coding for AIR9-like proteins (shown in this order: gene1 EAY10472, gene2 EAY06037, gene3 EAX99086, gene4 EAY04681, gene5 EAX86457). (B) Phylogenetic tree showing key eukaryotic taxa. All organisms found to encode AIR9-like proteins are highlighted in green. Numbers in parenthesis indicate tested genomes devoid of AIR9-like proteins. This phylogenetic tree has been redrawn and is based on results published elsewhere.⁷,¹⁶,¹⁷