Gene structures of PrxQ in Arabidopsis thaliana (At), Selaginella moellendorffii (Sm), Physcomitrella patens (Pp) and Chlamydomonas reinhardtii (Cr). Expressed PrxQ genes are shown in green, non-expressed in blue. The vertical lines connect corresponding splice sites. The numbers represent positions of corresponding amino acids in the alignment shown in Fig. 8A the relative splice site within the corresponding codon.