論文 - 詳細
| RRC ID | 35306 |
|---|---|
| 著者 | Desai KK, Miller BG. |
| タイトル | Recruitment of genes and enzymes conferring resistance to the nonnatural toxin bromoacetate. |
| ジャーナル | Proc Natl Acad Sci U S A |
| Abstract |
Microbial niches contain toxic chemicals capable of forcing organisms into periods of intense natural selection to afford survival. Elucidating the mechanisms by which microbes evade environmental threats has direct relevance for understanding and combating the rise of antibiotic resistance. In this study we used a toxic small-molecule, bromoacetate, to model the selective pressures imposed by antibiotics and anthropogenic toxins. We report the results of genetic selection experiments that identify nine genes from Escherichia coli whose overexpression affords survival in the presence of a normally lethal concentration of bromoacetate. Eight of these genes encode putative transporters or transmembrane proteins, while one encodes the essential peptidoglycan biosynthetic enzyme, UDP-N-acetylglucosamine enolpyruvoyl transferase (MurA). Biochemical studies demonstrate that the primary physiological target of bromoacetate is MurA, which becomes irreversibly inactivated via alkylation of a critical active-site cysteine. We also screened a comprehensive library of E. coli single-gene deletion mutants and identified 63 strains displaying increased susceptibility to bromoacetate. One hypersensitive bacterium lacks yliJ, a gene encoding a predicted glutathione transferase. Herein, YliJ is shown to catalyze the glutathione-dependent dehalogenation of bromoacetate with a k(cat)/K(m) value of 5.4 × 10(3) M(-1) s(-1). YliJ displays exceptional substrate specificity and produces a rate enhancement exceeding 5 orders of magnitude, remarkable characteristics for reactivity with a nonnatural molecule. This study illustrates the wealth of intrinsic survival mechanisms that can be exploited by bacteria when they are challenged with toxins. |
| 巻・号 | 107(42) |
| ページ | 17968-73 |
| 公開日 | 2010-10-19 |
| DOI | 10.1073/pnas.1007559107 |
| PII | 1007559107 |
| PMID | 20921376 |
| PMC | PMC2964223 |
| MeSH | Acetates / toxicity* Drug Resistance, Microbial / genetics Escherichia coli / enzymology* Escherichia coli / genetics* Genome, Bacterial Glutathione Transferase / metabolism |
| IF | 9.412 |
| 引用数 | 18 |
| WOS 分野 | BIOCHEMISTRY & MOLECULAR BIOLOGY |
| オルトメトリクス指標 |
オルトメトリクス指標項目
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| 最多言及媒体 | Policy sources |
| 各媒体での言及数の合計 | 2 |
| 過去6か月間でのオルトメトリクス指標の変動値 | 0.0 |
| リソース情報 | |
| 原核生物(大腸菌) | Keio collection |