Multidisciplinary approaches shed light on biosynthesis and unusual structural features of the antimicrobial hybrid NRPS/PKS-synthesized albicidin

Cociancich Stéphane. 2017. Multidisciplinary approaches shed light on biosynthesis and unusual structural features of the antimicrobial hybrid NRPS/PKS-synthesized albicidin. . Toulouse : s.n., Résumé, 1 p. MicrobiOccitanie 2017. 1, Toulouse, France, 24 Avril 2017/26 Avril 2017.

Résumé : Albicidin is a potent DNA gyrase inhibitor produced by the sugarcane pathogenic bacterium Xanthomonas albilineans. It blocks the differentiation of chloroplasts, resulting in appearance of narrow white stripes on sugarcane leaves that are characteristic of leaf scald disease. Albicidin targets the bacterial gyrase by a mechanism that is different from the one of any other known DNA gyrases inhibitors [1]. It exhibits antibacterial activity at nanomolar concentrations against Escherichia coli and to a lower extent against numerous human pathogenic bacteria [2]. A decade of intense work was necessary to decipher albicidin's biosynthetic pathway and to elucidate its astonishing never-seen-before structure. Albicidin is produced by a hybrid PKS/NRPS system. Such ribosome-independent systems consist of modular megasynthetases which operate in an assembly-line fashion to activate, modify and link mostly unusual aminoacid building blocks, finally resulting in complex bioactive peptide-like molecules. The structure of albicidin, which was predicted by former in silico sequence analyses of its PKS/NRPS gene cluster [3], was ascertained by means of mass spectrometry and NMR spectroscopy. We demonstrated that albicidin exhibits a linear polyaromatic penta-peptidic structure containing the rare aminoacids para-aminobenzoate and cyanoalanine [4]. The determination of the structure of albicidin allowed the development of a protocol for the chemical synthesis of this complex molecule [5]. Consequently, new research, such as structure-activity relationship studies, will now be possible.

Classification Agris : 000 - Autres thèmes
H20 - Maladies des plantes

Auteurs et affiliations

• Cociancich Stéphane, CIRAD-BIOS-UMR BGPI (FRA)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/584722/)

Métriques

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