p-Hydroxybenzoic acid synthesis in Mycobacterium tuberculosis.
Research output: Contribution to journal › Journal article › Research › peer-review
Glycosylated p-hydroxybenzoic acid methyl esters and structurally related phenolphthiocerol glycolipids are important virulence factors of Mycobacterium tuberculosis. Although both types of molecules are thought to be derived from p-hydroxybenzoic acid, the origin of this putative biosynthetic precursor in mycobacteria remained to be established. We describe the characterization of a transposon mutant of M. tuberculosis deficient in the production of all forms of p-hydroxybenzoic acid derivatives. The transposon was found to be inserted in Rv2949c, a gene located in the vicinity of the polyketide synthase gene pks15/1, involved in the elongation of p-hydroxybenzoate to phenolphthiocerol in phenolic glycolipid-producing strains. A recombinant form of the Rv2949c enzyme was produced in the fast-growing non-pathogenic Mycobacterium smegmatis and purified to near homogeneity. The recombinant enzyme catalyzed the removal of the pyruvyl moiety of chorismate to form p-hydroxybenzoate with an apparent K(m) value for chorismate of 19.7 microm and a k(cat) value of 0.102 s(-1). Strong inhibition of the reaction by p-hydroxybenzoate but not by pyruvate was observed. These results establish Rv2949c as a chorismate pyruvate-lyase responsible for the direct conversion of chorismate to p-hydroxybenzoate and identify Rv2949c as the sole enzymatic source of p-hydroxybenzoic acid in M. tuberculosis.
Original language | English |
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Journal | Journal of Biological Chemistry |
Volume | 280 |
Issue number | 49 |
Pages (from-to) | 40699-706 |
Number of pages | 7 |
ISSN | 0021-9258 |
DOIs | |
Publication status | Published - 2005 |
Externally published | Yes |
Bibliographical note
Keywords: Chorismic Acid; DNA Transposable Elements; Escherichia coli; Methylation; Mutation; Mycobacterium smegmatis; Mycobacterium tuberculosis; Oxo-Acid-Lyases; Parabens; Phenotype; Polyketide Synthases; Pyruvic Acid; Recombinant Proteins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
ID: 5016824