(A) The predicted protein structure of EXA1. The GYF domain is indicated by a gray box. (B) Amino acid alignments of GYF domains from eukaryotes. At, Sc, Hs, Mm, Pp, Os, Dm, Dr and Ce stand for the following species: A. thaliana, Saccharomyces cerevisiae (SYH1P: AJW09613.1; SMY2P: AJQ12401.1), Homo sapiens (CD2BP2: ALQ33977.1), Mus musculus (GIGYF2: EDL40166.1), Physcomitrella patens (XP_001772117.1), Oryza sativa (XP_015646509.1), Drosophila melanogaster (NP_651950.3), Danio rerio (XP_009301398.1) and Caenorhabditis elegans (NP_001041150.1), respectively. Protein sequences were aligned using CLUSTAL. Residues that are characteristic of GYF domains are depicted as red letters. The green or blue letters represent residues conserved in either the CD2BP2 or SMY2 subfamily, respectively. (C) EXA1 and its potential orthologs in plant species were used to generate the phylogenetic tree. Putative EXA1 orthologs were obtained from Plaza using full-length protein sequences as input. Sequences were aligned using Muscle and a Neighbor Joining tree was constructed using MEGA 5.0 with the JTT model and 5000 bootstrap value.