Comparison of the AtHEMN amino acid sequence with CPO polypeptides of Arabidopsis and other plant species. A, Alignment of AtHEMN1 (At5g63290) with CPOs (hemF) of Arabidopsis (i.e. LIN2 and HEMF2). AtHEMN1 shows low homology with hemF. B, Alignment of AtHEMN1 (At5g63290) with hemN polypeptides of Camelina sativa, Brassica rapa, Citrus, Oryza sativa, Glycine, Ricinus communis, and maize. Identical residues are marked in gray. The Elp3 and hemN domains are marked with thick lines and labeled. AtHEMN1 shows high homology with the known hemN sequences.