Abstract
Ferrochelatase (FeCh) is an enzyme involved in the terminal step of heme biosynthesis. In green plants, its activity has been reported in both plastids and mitochondria. However, the subcellular localization of the FeCh have been the subject of much discussion, because there is no strong evidence for localization of FeCh in plant mitochondria.
Cyanidioscyzon merolae is a unicellular red alga that contains one cell nucleus, one chloroplast and one mitochondrion, and is proposed as the primitive phototrophic eukaryote. In this study, subcellular localization of FeCh in C. merolae was investigated by transgenic analysis. Immunofluorescence microscopy revealed that HA-tagged FeCh is located in mitochondrion. In addition, phylogenic analysis indicated that C. merolae FeCh sequence did not show monophyly with those from green plants. These results suggests that C. merolae FeCh is distinct from that of green plants. The relationship between FeCh localization and evolutionary consequence is discussed.
