論文 - 詳細
| RRC ID | 58143 |
|---|---|
| 著者 | Katsube S, Ando T, Yoneyama H. |
| タイトル | L-Alanine Exporter, AlaE, of Escherichia coli Functions as a Safety Valve to Enhance Survival under Feast Conditions. |
| ジャーナル | Int J Mol Sci |
| Abstract |
The intracellular level of amino acids is determined by the balance between their anabolic and catabolic pathways. L-alanine is anabolized by three L-alanine synthesizing enzymes and catabolized by two racemases and D-amino acid dehydrogenase (DadA). In addition, its level is regulated by L-alanine movement across the inner membrane. We identified the novel gene alaE, encoding an L-alanine exporter. To elucidate the physiological function of L-Alanine exporter, AlaE, we determined the susceptibility of alaE-, dadA-, and alaE/dadA-deficient mutants, derived from the wild-type strain MG1655, to L-alanyl-L-alanine (Ala-Ala), which shows toxicity to the L-alanine-nonmetabolizing variant lacking alaE. The dadA-deficient mutant has a similar minimum inhibitory concentration (MIC) (>1.25 mg/mL) to that observed in MG1655. However, alaE- and alaE/dadA-deficient mutants had MICs of 0.04 and 0.0025 mg/mL, respectively. The results suggested that the efficacy of AlaE to relieve stress caused by toxic intracellular accumulation of L-alanine was higher than that of DadA. Consistent with this, the intracellular level of alanine in the alaE-mutant was much higher than that in MG1655 and the dadA-mutant. We, therefore, conclude that AlaE functions as a 'safety-valve' to prevent the toxic level accumulation of intracellular L-alanine under a peptide-rich environment, such as within the animal intestine. |
| 巻・号 | 20(19) |
| 公開日 | 2019-10-7 |
| DOI | 10.3390/ijms20194942 |
| PII | ijms20194942 |
| PMID | 31591285 |
| PMC | PMC6801825 |
| MeSH | Alanine / metabolism* Alanine / toxicity Amino Acid Transport Systems, Neutral / genetics Amino Acid Transport Systems, Neutral / metabolism* Biological Transport D-Amino-Acid Oxidase / genetics* D-Amino-Acid Oxidase / metabolism Escherichia coli / genetics Escherichia coli / growth & development* Escherichia coli / metabolism Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism* Microbial Sensitivity Tests Microbial Viability Mutation Stress, Physiological |
| IF | 4.556 |
| 引用数 | 1 |
| 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 | Patent(IFI CLAIMS) |
| 各媒体での言及数の合計 | 1 |
| 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) | E. coli JW1178 E. coli JW2645 |