Discovery of a novel dehydratase of the fatty acid synthase type II critical for ketomycolic acid biosynthesis and virulence of Mycobacterium tuberculosis
3TWB - Toulouse White Biotechnology (Toulouse White Biotechnology
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Abstract : The fatty acid synthase type II (FAS-II) multienzyme system builds the main chain of mycolic acids (MAs), important lipid pathogenicity factors of Mycobacterium tuberculosis (Mtb). Due to their original structure, the identification of the (3 R)-hydroxyacyl-ACP dehydratases, HadAB and HadBC, of Mtb FAS-II complex required in-depth work. Here, we report the discovery of a third dehydratase protein, HadDMtb (Rv0504c), whose gene is non-essential and sits upstream of cmaA2 encoding a cyclopropane synthase dedicated to keto- and methoxy-MAs. HadDMtb deletion triggered a marked change in Mtb keto-MA content and size distribution, deeply impacting the production of full-size molecules. Furthermore, abnormal MAs, likely generated from 3-hydroxylated intermediates, accumulated. These data strongly suggest that HadDMtb catalyzes the 3-hydroxyacyl dehydratation step of late FAS-II elongation cycles during keto-MA biosynthesis. Phenotyping of Mtb hadD deletion mutant revealed the influence of HadDMtb on the planktonic growth, colony morphology and biofilm structuration, as well as on low temperature tolerance. Importantly, HadDMtb has a strong impact on Mtb virulence in the mouse model of infection. The effects of the lack of HadDMtb observed both in vitro and in vivo designate this protein as a bona fide target for the development of novel anti-TB intervention strategies.
https://hal-pasteur.archives-ouvertes.fr/pasteur-02474005 Contributor : Laurence LanglaisConnect in order to contact the contributor Submitted on : Tuesday, February 11, 2020 - 10:14:13 AM Last modification on : Wednesday, June 1, 2022 - 3:54:25 AM
Cyril Lefebvre, Wafa Frigui, Nawel Slama, Françoise Lauzeral-Vizcaino, Patricia Constant, et al.. Discovery of a novel dehydratase of the fatty acid synthase type II critical for ketomycolic acid biosynthesis and virulence of Mycobacterium tuberculosis. Scientific Reports, Nature Publishing Group, 2020, 10 (1), pp.2112. ⟨10.1038/s41598-020-58967-8⟩. ⟨pasteur-02474005⟩