Coenzyme Synthesis in Plant Mitochondria

Open Access article: http://4e.plantphys.net/article.php?ch=11&id=358The synthesis of many biological compounds and the regulation of several metabolic processes require the addition or removal of one-carbon units (C1-units). Tetrahydrofolate derivatives (vitamin B9) mediate most of these transfers of C1-units, directly or indirectly, via S-adenosylmethionine. Some enzymes involved in CO2 manipulation during carboxylation, decarboxylation, and transcarboxylation reactions utilize another essential cofactor, biotin (vitamin B8). Unlike plants and some fungi and bacteria, mammals cannot synthesize tetrahydrofolate or biotin de novo and depend entirely on their dietary supply. The aim of the present Essay is to summarize recent progress in elucidating the tetrahydrofolate and biotin biosynthetic pathways in plants, with an emphasis on the essential role of mitochondria in these complex networks