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Feedback inhibition of 1‐deoxy‐D‐xylulose 5‐phosphate synthase (DXS) regulates the 2‐C‐methyl‐D‐erythritol 4‐ phosphate (MEP) pathway
Author(s) -
Banerjee Aparajita,
Wu Yan,
Banerjee Rahul,
Li Yue,
Yan Honggao,
Sharkey Thomas D.
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.lb119
Subject(s) - enzyme , biochemistry , chemistry , terpenoid , metabolic pathway , atp synthase , lyase , thiamine , biosynthesis , stereochemistry
The 2‐ C ‐methyl‐ d ‐erythritol 4‐phosphate (MEP) pathway constitutes an important metabolic pathway for the biosynthesis of isopentenyl diphosphate (IDP) and dimethylallyl diphosphate (DMADP), the precursors for isoprene and other higher isoprenoids. The goal of this study was to understand the regulation of the MEP pathway. It was suggested from previous studies that the first enzyme of the MEP pathway, 1‐deoxy‐ d ‐xylulose 5‐phosphate synthase (DXS), could have significant regulatory role. In order to test that the DXS enzyme was cloned from Populus trichocarpa and the recombinant protein ( Pt DXS) was purified from E. coli . An LC‐MS/MS based assay was developed for studying the regulation of Pt DXS activity. Pt DXS was found to be inhibited by IDP and DMADP. Further studies show that both of these metabolites compete with thiamine diphosphate for binding with the enzyme. Computational analysis shows that IDP and DMADP bind with the enzyme in a manner very similar to the binding of thiamine diphosphate. The feedback inhibition of Pt DXS by IDP and DMADP constitutes an important mechanism of metabolic regulation of the MEP pathway. This work was supported by the US National Science Foundation (Grant IOS‐0950574). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.