Publications

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

  Suvarna K., Stevenson D., Meganathan R., Hudspeth M.E.S.

  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 chai ... >> More

  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. << Less

  J. Bacteriol. 180:2782-2787(1998) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Biosynthesis of bacterial menaquinones: the membrane-associated 1,4-dihydroxy-2-naphthoate octaprenyltransferase of Escherichia coli.

  Shineberg B., Young I.G.

  It has been postulated that 1,4-dihydroxy-2-naphthoic acid is the naphthalenic intermediate in the biosynthesis of menaquinone (vitamin K2) in Escherichia coli to which the octaprenyl side chain is attached to from demethylmenaquinone. In the present work the presence of enzyme, 1,4-dihydroxy-2-na ... >> More

  It has been postulated that 1,4-dihydroxy-2-naphthoic acid is the naphthalenic intermediate in the biosynthesis of menaquinone (vitamin K2) in Escherichia coli to which the octaprenyl side chain is attached to from demethylmenaquinone. In the present work the presence of enzyme, 1,4-dihydroxy-2-naphthoate octaprenyltransferase, which catalyzes the conversion of 1,4-dihydroxy-2-naphthoate to demethylmenaquinone was demonstrated in cell extracts of E. coli. Demethylmenaquinone-9 was formed when the naphthoate was incubated with cell extracts and the synthetic substrate, solanesyl pyrophosphate, in the presence of Triton X-100. Solanesyl monophosphate could not substitute for the pyrophosphate in the reaction. The prenylation of of 1,4-dihydroxy-2-naphthoate was also studied in a strain of E. coli which accumulates octaprenyl pyrophosphate, the natural precursor of the menaquinone side chain. The octaprenyltransferase was shown to be membrane bound and to require magnesium ions for optimal activity. A menA-mutant of E. coli was found to lack the octaprenyltransferase activity, suggesting that the menA gene is the structural gene for this enzyme. However, this strain had normal levels of 4-hydroxybenzoate octaprenyltransferase, the enzyme catalyzing the analogous prenylation reaction in ubiquinone biosynthesis, providing additional evidence that the two octaprenyltransferases are quite distinct. << Less

  Biochemistry 15:2754-2758(1976) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.

• Biosynthesis of menaquinones. Enzymatic prenylation of 1,4-dihydroxy-2-naphthoate by Micrococcus luteus membrane fractions.

  Saito Y., Ogura K.

  1,4-Dihydroxy-2-naphthoate:polyprenyltransferase was detected in the membrane fraction from Micrococcus luteus. The specificity of the enzyme ws so tolerant as regards the prenyl-donating substrate that prenyl pyrophosphates ranging in chain length from C15 to C45 were active as substrates. The mo ... >> More

  1,4-Dihydroxy-2-naphthoate:polyprenyltransferase was detected in the membrane fraction from Micrococcus luteus. The specificity of the enzyme ws so tolerant as regards the prenyl-donating substrate that prenyl pyrophosphates ranging in chain length from C15 to C45 were active as substrates. The monophosphate esters were also active, though the reactivities were much lower than those of the corresponding pyrophosphates. The enzyme showed rigorous specificity with respect to the aromatic substrate. Neither 1,4-dihydroxynaphthalene nor its 2-methyl derivative was active at all. 1,4-Dihydroxy-3-methyl-2-naphthoate could be prenylated to afford menaquinone, but the reactivity was much less than that of its demethyl derivative. These results support the view that menaquinone biosynthesis involves the prenylation of 1,4-dihydroxy-2-naphthoate prior to decarboxylation or methylation. << Less

  J Biochem 89:1445-1452(1981) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.