Phylloquinone (vitamin K(1) ) biosynthesis in plants: two peroxisomal thioesterases of Lactobacillales origin hydrolyze 1,4-dihydroxy-2-naphthoyl-CoA

Plant J. 2012 Jul;71(2):205-15. doi: 10.1111/j.1365-313X.2012.04972.x. Epub 2012 Jun 19.


It is not known how plants cleave the thioester bond of 1,4-dihydroxy-2-naphthoyl-CoA (DHNA-CoA), a necessary step to form the naphthoquinone ring of phylloquinone (vitamin K(1) ). In fact, only recently has the hydrolysis of DHNA-CoA been demonstrated to be enzyme driven in vivo, and the cognate thioesterase characterized in the cyanobacterium Synechocystis. With a few exceptions in certain prokaryotic (Sorangium and Opitutus) and eukaryotic (Cyanidium, Cyanidioschyzon and Paulinella) organisms, orthologs of DHNA-CoA thioesterase are missing outside of the cyanobacterial lineage. In this study, genomic approaches and functional complementation experiments identified two Arabidopsis genes encoding functional DHNA-CoA thioesterases. The deduced plant proteins display low percentages of identity with cyanobacterial DHNA-CoA thioesterases, and do not even share the same catalytic motif. GFP-fusion experiments demonstrated that the Arabidopsis proteins are targeted to peroxisomes, and subcellular fractionations of Arabidopsis leaves confirmed that DHNA-CoA thioesterase activity occurs in this organelle. In vitro assays with various aromatic and aliphatic acyl-CoA thioester substrates showed that the recombinant Arabidopsis enzymes preferentially hydrolyze DHNA-CoA. Cognate T-DNA knock-down lines display reduced DHNA-CoA thioesterase activity and phylloquinone content, establishing in vivo evidence that the Arabidopsis enzymes are involved in phylloquinone biosynthesis. Extraordinarily, structure-based phylogenies coupled to comparative genomics demonstrate that plant DHNA-CoA thioesterases originate from a horizontal gene transfer with a bacterial species of the Lactobacillales order.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Acyl Coenzyme A / metabolism*
  • Arabidopsis / cytology
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / isolation & purification
  • Arabidopsis Proteins / metabolism
  • Bacterial Proteins / genetics
  • Gene Knockout Techniques
  • Gene Transfer, Horizontal
  • Genetic Complementation Test
  • Genomics
  • Genotype
  • Hydrolysis
  • Lactobacillales / enzymology*
  • Lactobacillales / genetics
  • Mutagenesis, Insertional
  • Peroxisomes / enzymology*
  • Peroxisomes / metabolism
  • Phylogeny
  • Plant Leaves / enzymology
  • Plant Leaves / metabolism
  • Recombinant Fusion Proteins
  • Substrate Specificity
  • Synechocystis / enzymology
  • Synechocystis / genetics
  • Thiolester Hydrolases / genetics*
  • Thiolester Hydrolases / isolation & purification
  • Thiolester Hydrolases / metabolism
  • Vitamin K 1 / analogs & derivatives*
  • Vitamin K 1 / chemistry
  • Vitamin K 1 / metabolism*
  • Vitamins / chemistry
  • Vitamins / metabolism*


  • Acyl Coenzyme A
  • Arabidopsis Proteins
  • Bacterial Proteins
  • Recombinant Fusion Proteins
  • Vitamins
  • Vitamin K 1
  • Thiolester Hydrolases