Impact of the epoxide hydrolase EphD on the metabolism of mycolic acids in mycobacteria

Madacki, Jan; Laval, Françoise; Grzegorzewicz, Anna E.; Lemassu, Anne; Záhorszká, Monika; Arand, Michael; McNeil, Michael; Daffé, Mamadou; Jackson, Mary; Lanéelle, Marie‐Antoinette; Korduláková, Jana

doi:10.1074/jbc.ra117.000246

Cited by 24 publications

(26 citation statements)

References 61 publications

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“…The plate was developed by staining in 10% cupric sulfate and charring. Assignments of lipids were performed using Madacki et al ( 42 ) as a reference.…”

Section: Methodsmentioning

confidence: 99%

Polysaccharide length affects mycobacterial cell shape and antibiotic susceptibility

et al. 2020

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Bacteria control the length of their polysaccharides, which can control cell viability, physiology, virulence, and immune evasion. Polysaccharide chain length affects immunomodulation, but its impact on bacterial physiology and antibiotic susceptibility was unclear. We probed the consequences of truncating the mycobacterial galactan, an essential linear polysaccharide of about 30 residues. Galactan covalently bridges cell envelope layers, with the outermost cell wall linkage point occurring at residue 12. Reducing galactan chain length by approximately half compromises fitness, alters cell morphology, and increases the potency of hydrophobic antibiotics. Systematic variation of the galactan chain length revealed that it determines periplasm size. Thus, glycan chain length can directly affect cellular physiology and antibiotic activity, and mycobacterial glycans, not proteins, regulate periplasm size.

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“…The plate was developed by staining in 10% cupric sulfate and charring. Assignments of lipids were performed using Madacki et al ( 42 ) as a reference.…”

Section: Methodsmentioning

confidence: 99%

Polysaccharide length affects mycobacterial cell shape and antibiotic susceptibility

et al. 2020

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“…4). Seven of these eight genes are involved in cell wall, lipid, or arabinan metabolism (pks2, phoR, mmaA3, cmaA2, ephD, rv1184c, and rv3822) (38)(39)(40)(41)(42)(43), suggesting that the permeability of the mycobacterial envelope is the primary determinant of RIF activity during infection. The PZA/HRZE dimension is associated with pncA, the activator of the prodrug PZA, as well as mutations in the ppe51 gene that is involved in glycerol/glucose uptake (44) and was previously found to enhance the activity of HRZE (36) (Fig.…”

Section: Selection Of Transposon Mutant Libraries In Antibiotic-treatmentioning

confidence: 99%

Distinct Bacterial Pathways Influence the Efficacy of Antibiotics against Mycobacterium tuberculosis

et al. 2020

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Effective tuberculosis treatment requires at least 6 months of combination therapy. Alterations in the physiological state of the bacterium during infection are thought to reduce drug efficacy and prolong the necessary treatment period, but the nature of these adaptations remain incompletely defined. To identify specific bacterial functions that limit drug effects during infection, we employed a comprehensive genetic screening approach to identify mutants with altered susceptibility to the first-line antibiotics in the mouse model. We identified many mutations that increase the rate of bacterial clearance, suggesting new strategies for accelerating therapy. In addition, the drug-specific effects of these mutations suggested that different antibiotics are limited by distinct factors. Rifampin efficacy is inferred to be limited by cellular permeability, whereas isoniazid is preferentially affected by replication rate. Many mutations that altered bacterial clearance in the mouse model did not have an obvious effect on drug susceptibility using in vitro assays, indicating that these chemical-genetic interactions tend to be specific to the in vivo environment. This observation suggested that a wide variety of natural genetic variants could influence drug efficacy in vivo without altering behavior in standard drug-susceptibility tests. Indeed, mutations in a number of the genes identified in our study are enriched in drug-resistant clinical isolates, identifying genetic variants that may influence treatment outcome. Together, these observations suggest new avenues for improving therapy, as well as the mechanisms of genetic adaptations that limit it. IMPORTANCE Understanding how Mycobacterium tuberculosis survives during antibiotic treatment is necessary to rationally devise more effective tuberculosis (TB) chemotherapy regimens. Using genome-wide mutant fitness profiling and the mouse model of TB, we identified genes that alter antibiotic efficacy specifically in the infection environment and associated several of these genes with natural genetic variants found in drug-resistant clinical isolates. These data suggest strategies for synergistic therapies that accelerate bacterial clearance, and they identify mechanisms of adaptation to drug exposure that could influence treatment outcome.

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“…3.3.2.8) 10 . At present, four of these genes have been confirmed to produce proteins with resulting enzymatic activity of an epoxide hydrolase (ephA this work , ephB 11,12 , ephD 13 , ephG 10 ). The idea to use mycobacterial EHs as potential drug targets was recently emphasized by screening of a large compound library in a whole cell phenotypic minimum inhibitory concentration (MIC) assay, which pointed towards EHs as the main target of the lead compound 14 .…”

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confidence: 88%

The crystal structure of mycobacterial epoxide hydrolase A

Schulz

Henderson

Illarionov

et al. 2020

Sci Rep

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The human pathogen Mycobacterium tuberculosis is the causative agent of tuberculosis resulting in over 1 million fatalities every year, despite decades of research into the development of new anti-TB compounds. Unlike most other organisms M. tuberculosis has six putative genes for epoxide hydrolases (EH) of the α/β-hydrolase family with little known about their individual substrates, suggesting functional significance for these genes to the organism. Due to their role in detoxification, M. tuberculosis EH’s have been identified as potential drug targets. Here, we demonstrate epoxide hydrolase activity of M. thermoresistibile epoxide hydrolase A (Mth-EphA) and report its crystal structure in complex with the inhibitor 1,3-diphenylurea at 2.0 Å resolution. Mth-EphA displays high sequence similarity to its orthologue from M. tuberculosis and generally high structural similarity to α/β-hydrolase EHs. The structure of the inhibitor bound complex reveals the geometry of the catalytic residues and the conformation of the inhibitor. Comparison to other EHs from mycobacteria allows insight into the active site plasticity with respect to substrate specificity. We speculate that mycobacterial EHs may have a narrow substrate specificity providing a potential explanation for the genetic repertoire of epoxide hydrolase genes in M. tuberculosis.

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Impact of the epoxide hydrolase EphD on the metabolism of mycolic acids in mycobacteria

Cited by 24 publications

References 61 publications

Polysaccharide length affects mycobacterial cell shape and antibiotic susceptibility

Polysaccharide length affects mycobacterial cell shape and antibiotic susceptibility

Distinct Bacterial Pathways Influence the Efficacy of Antibiotics against Mycobacterium tuberculosis

The crystal structure of mycobacterial epoxide hydrolase A

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