Isolation, structural studies and chemical synthesis of a ‘palmitone lipid’ from Corynebacterium diphtheriae

Ahibo‐Coffy, Antoine; Aurelle, Hélène; Lacave, Charlotte; Promé, Jean‐Claude; Puzo, Germain; Savagnac, Arlette

doi:10.1016/0009-3084(78)90025-7

Cited by 24 publications

(6 citation statements)

References 9 publications

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“…7A, lane 2), suggesting that a secondary saponification reaction has occurred and has led to the formation of long chain ketones (Fig. 7C) (23). After reduction by NaBH 4 , these spots disappeared and, concomitantly, two new spots were observed at the same R f as the two synthetic racemic (1R,2R and 1R,2S) C32 corynomycolates, and one at a R f similar to that of hentriacontanol (Fig.…”

Section: Binding Of the Carboxyacyl Chain To The At Domain And Transfmentioning

confidence: 90%

The Pks13/FadD32 Crosstalk for the Biosynthesis of Mycolic Acids in Mycobacterium tuberculosis

Gavalda

Léger

Rest

et al. 2009

Journal of Biological Chemistry

110

115

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The last steps of the biosynthesis of mycolic acids, essential and specific lipids of Mycobacterium tuberculosis and related bacteria, are catalyzed by proteins encoded by the fadD32-pks13-accD4 cluster. Here, we produced and purified an active form of the Pks13 polyketide synthase, with a phosphopantetheinyl (P-pant) arm at both positions Ser-55 and Ser-1266 of its two acyl carrier protein (ACP) domains. Combination of liquid chromatography-tandem mass spectrometry of protein tryptic digests and radiolabeling experiments showed that, in vitro, the enzyme specifically loads long-chain 2-carboxyacyl-CoA substrates onto the P-pant arm of its C-terminal ACP domain via the acyltransferase domain. The acyl-AMPs produced by the FadD32 enzyme are specifically transferred onto the ketosynthase domain after binding to the P-pant moiety of the N-terminal ACP domain of Pks13 (N-ACP Pks13 ). Unexpectedly, however, the latter step requires the presence of active FadD32. Thus, the couple FadD32-(N-ACP Pks13 ) composes the initiation module of the mycolic condensation system. Pks13 ultimately condenses the two loaded fatty acyl chains to produce ␣-alkyl ␤-ketoacids, the precursors of mycolic acids. The developed in vitro assay will constitute a strategic tool for antimycobacterial drug screening.

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Section: Binding Of the Carboxyacyl Chain To The At Domain And Transfmentioning

confidence: 90%

The Pks13/FadD32 Crosstalk for the Biosynthesis of Mycolic Acids in Mycobacterium tuberculosis

Gavalda

Léger

Rest

et al. 2009

Journal of Biological Chemistry

110

115

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“…Cell-free extracts of Corynebacterium have been shown to utilize [ 14 C]palmitic acid (17,18), with the newly synthesized mycolic acid exclusively labeled at C-1 and C-3 (19). The Claisen condensation reaction was hypothesized to involve a carboxylation step since it is inhibited by avidin, an inhibitor of biotin-dependent enzymes in extracts of Corynebacterium diphtheriae that produces the putative precursor of mycolic acids, 2-tetradecyl-3-oxo-octadecanoic acid (19,20). In contrast, avidin has no effect on the Claisen condensation reaction in a cell-free extract of Corynebacterium matruchotii, which synthesizes mature mycolic acids (17,18).…”

Section: Mycolic Acids Are Long Chain ␣-Alkyl-␤-hydroxylated Fatty Acmentioning

confidence: 99%

Acyl-CoA Carboxylases (accD2 and accD3), Together with a Unique Polyketide Synthase (Cg-pks), Are Key to Mycolic Acid Biosynthesis in Corynebacterianeae Such as Corynebacterium glutamicum and Mycobacterium tuberculosis

Gande

Gibson

Brown

et al. 2004

Journal of Biological Chemistry

162

164

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The Corynebacterianeae such as Corynebacterium glutamicum and Mycobacterium tuberculosis possess several unique and structurally diverse lipids, including the genus-specific mycolic acids. Although the function of a number of genes involved in fatty acid and mycolic acid biosynthesis is known, information relevant to the initial steps within these biosynthetic pathways is relatively sparse. Interestingly, the genomes of Corynebacterianeae possess a high number of accD genes, whose gene products resemble the ␤-subunit of the acetyl-CoA carboxylase of Escherichia coli, providing the activated intermediate for fatty acid synthesis. We present here our studies on four putative accD genes found in C. glutamicum. Although growth of the accD4 mutant remained unchanged, growth of the accD1 mutant was strongly impaired and partially recovered by the addition of exogenous oleic acid. Overexpression of accD1 and accBC, encoding the carboxylase ␣-subunit, resulted in an 8-fold increase in malonyl-CoA formation from acetyl-CoA in cell lysates, providing evidence that accD1 encodes a carboxyltransferase involved in the biosynthesis of malonyl-CoA. Interestingly, fatty acid profiles remained unchanged in both our accD2 and accD3 mutants, but a complete loss of mycolic acids, either as organic extractable trehalose and glucose mycolates or as cell wall-bound mycolates, was observed. These two carboxyltransferases are also retained in all Corynebacterianeae, including Mycobacterium leprae, constituting two distinct groups of orthologs. Furthermore, carboxyl fixation assays, as well as a study of a Cg-pks deletion mutant, led us to conclude that accD2 and accD3 are key to mycolic acid biosynthesis, thus providing a carboxylated intermediate during condensation of the mero-chain and ␣-branch directed by the pks-encoded polyketide synthase. This study illustrates that the high number of accD paralogs have evolved to represent specific variations on the well known basic theme of providing carboxylated intermediates in lipid biosynthesis.

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“…Arthrobacter, Co~Tnebacteria, Mycobacteria, Nocardia 18,135,136) and Brevibacteriwn thiogenitalis 641 other intermediates such as monosaccharide acylates, glucose corynomycolates, e,,~'-trehalose-6-(3-oxo-2-tetradecanyl) octadecanoate and/or ~-~'-trehalose-6-mycolate-6-acetate of glycomycolate biosynthesis have been detected 64, 135-~38~. This indicates, that in other genera the synthesis of mycolates may occur via other sequences which differ with respect to the status of the generation of the first ester linkage, i.e., the introduction of the respective sugar components into the lipid synthesis and with respect to the kind of the sugar as well as to the sequence of esterification.…”

Section: Mycolic Acid Derivativesmentioning

confidence: 99%

Extracellular microbial lipids as biosurfactants

et al.

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Isolation, structural studies and chemical synthesis of a ‘palmitone lipid’ from Corynebacterium diphtheriae

Cited by 24 publications

References 9 publications

The Pks13/FadD32 Crosstalk for the Biosynthesis of Mycolic Acids in Mycobacterium tuberculosis

The Pks13/FadD32 Crosstalk for the Biosynthesis of Mycolic Acids in Mycobacterium tuberculosis

Acyl-CoA Carboxylases (accD2 and accD3), Together with a Unique Polyketide Synthase (Cg-pks), Are Key to Mycolic Acid Biosynthesis in Corynebacterianeae Such as Corynebacterium glutamicum and Mycobacterium tuberculosis

Extracellular microbial lipids as biosurfactants

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