Abstract
The enzyme 5,10‐methylenetetrahydrofolate dehydrogenase (MTHFD) is essential for the production of certain amino acids (glycine, serine, and methionine) and nucleic acids (thymidylate and purine). Here, we identified a cDNA encoding this enzyme from the silkworm Bombyx mori. The recombinant B. mori MTHFD (bmMTHFD) expressed in Escherichia coli recognized 5,10‐methylenetetrahydrofolate and 5,10‐methenyltetrahydrofolate as substrate in the presence of NADP + as well as NAD +. The bmMTHFD structure was determined at a resolution of 1.75 Å by X‐ray crystallography. Site‐directed mutagenesis indicated that the amino acid residue Tyr49 contributed to its catalytic activity. Our findings provide insight into the mechanism underlying the activity of MTHFD from B. mori and potentially other insects and may therefore facilitate the development of inhibitors specific to MTHFD as insecticides.
Highlights
One-carbon metabolism is involved in the synthesis of amino acids like alanine, glycine, and serine, as well as purine and pyrimidine bases [1,2]. 5,10-methylenetetrahydrofolate (MTHF) dehydrogenase (MTHFD; EC 1. 5.1.5) is an enzyme involved in one-carbon metabolism in eukaryotes [2]
Based on the phylogenetic tree generated from the aligned amino acid sequences of the methylenetetrahydrofolate dehydrogenase (MTHFD), the Bombyx mori MTHF dehydrogenase (bmMTHFD) cloned in this study belonged to an independent group including putative MTHFDs of insects (Fig. 2)
This study aimed to detect the presence of one-carbon metabolism in the silkworm B. mori and to analyze whether MTHFD is relevant for insecticide design
Summary
One-carbon metabolism is involved in the synthesis of amino acids like alanine, glycine, and serine, as well as purine and pyrimidine bases [1,2]. 5,10-methylenetetrahydrofolate (MTHF) dehydrogenase (MTHFD; EC 1. 5.1.5) is an enzyme involved in one-carbon metabolism in eukaryotes [2]. The prokaryotic MTHFD of Escherichia coli is a bifunctional enzyme that uses NADP+ [10], and the monofunctional enzyme of Abbreviations bmMTHFD, Bombyx mori 5,10-methylenetetrahydrofolate dehydrogenase; C, cyclohydrolase; D, dehydrogenase; MTHF, 5,10methylenetetrahydrofolate; MTHFD, 5,10-methylenetetrahydrofolate dehydrogenase; S, synthetase; WT, wild-type. Since many agricultural pests are lepidopteran insects, it is useful to investigate the amino acid residues present in the active site of bmMTHFD. Because MTHFD is involved in the synthesis of important biomolecules such as amino acids and purine and pyrimidine bases, the inhibitors could be effective insecticides against agricultural pests. The crystal structure of bmMTHFD and the identification of the amino acid residues involved in catalytic function in the current study may provide insights into the mechanism underlying MTHFD activity and could facilitate the development of inhibitors specific to MTHFD as insecticides. To the best of our knowledge, this study is the first to report on MTHFD in insects
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
