Coenzyme Synthesis in Plant Mitochondria
Résumé
The 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.
Mots clés
plant
Arabidopsis thaliana
metabolic pathway
mitochondria
vitamin
biosynthesis
coenzyme
biotin
folate
tetrahydrofolate
enzyme
biotin synthase
cysteine desulfurase
adrenodoxin reductase
dihydrofolate reductase
dihydropteroate synthase
thymidylate synthase
aminodeoxychorismate synthase
aminodeoxychorismate lyase
shikimate pathway
s-Adenosylmethionine