关键词: 叶酸, 叶酸代谢, 5-甲酰四氢叶酸环化连接酶

Abstract: Folates, including tetrahydrofolate and its kinds of derivatives, belong to water soluble B family (B9). As key co-factors in one-carbon transfer reactions, folates take parts in several metabolic pathways in almost all organisms. 5-formyltetrahydrofolate cycloligase (5FCL) was reported to catalyze the storage form of 5-formyltetrahydrofolate (5-CHO-THF) into active folate forms. Here, maize 5FCL was cloned and characterized. Zm5FCL contained a conserved 5-formyltetrahydrofolate cyclo-ligase superfamily domain and had high sequence consistency with its homologues. The in-vitro enzymatic assay of recombinant Zm5FCL protein expressed in Escherichia coli cells showed that Zm5FCL had conserved function of converting 5-CHO-THF into 5,10-methenyltetrahydrofolate (5,10-CH=THF), and over-expression analysis of Zm5FCL in Arabidopsis 5fcl mutant demonstrated that Zm5FCL could convert 5-CHO-THF into 5,10-methenyltetrahydrofolate (5,10-CH=THF), and then 5-methyltetrahydrofolate (5-CH3-THF). These results suggested that Zm5FCL was involved in folate metabolism,which was presumed that Zm5FCL played important roles in maize folate metabolism.

Key words: folates, folate metabolism, 5-formyltetrahydrofolate cycloligase