Menaquinone (vitamin K2) biosynthesis: localization and characterization of the menA gene from Escherichia coli

J Bacteriol. 1998 May;180(10):2782-7. doi: 10.1128/JB.180.10.2782-2787.1998.


A key reaction in the biosynthesis of menaquinone involves the conversion of the soluble bicyclic naphthalenoid compound 1, 4-dihydroxy-2-naphthoic acid (DHNA) to the membrane-bound demethylmenaquinone. The enzyme catalyzing this reaction, DHNA-octaprenyltransferase, attaches a 40-carbon side chain to DHNA. The menA gene encoding this enzyme has been cloned and localized to a 2.0-kb region of the Escherichia coli genome between cytR and glpK. DNA sequence analysis of the cloned insert revealed a 308-codon open reading frame (ORF), which by deletion analyses was shown to restore anaerobic growth of a menA mutant. Reverse-phase high-performance liquid chromatography analysis of quinones extracted from the orf-complemented cells independently confirmed the restoration of menaquinone biosynthesis, and similarly, analyses of isolated cell membranes for DHNA octaprenyltransferase activity confirmed the introduction of the menA product into the orf-complemented menA mutant. The validity of an ORF-associated putative promoter sequence was confirmed by primer extension analyses.

Publication types

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

MeSH terms

  • Alkyl and Aryl Transferases / genetics*
  • Alkyl and Aryl Transferases / metabolism*
  • Amino Acid Sequence
  • Bacterial Proteins / genetics*
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli Proteins*
  • Molecular Sequence Data
  • Naphthols / metabolism*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Vitamin K / biosynthesis*


  • Bacterial Proteins
  • Escherichia coli Proteins
  • Naphthols
  • Vitamin K
  • 1,4-dihydroxy-2-naphthoic acid
  • Alkyl and Aryl Transferases
  • 4-hydroxybenzoate polyprenyltransferase
  • MenA protein, E coli