論文

査読有り 国際誌
2021年3月

Characterization of aromatic acid/proton symporters in Pseudomonas putida KT2440 toward efficient microbial conversion of lignin-related aromatics.

Metabolic Engineering
  • Ayumu Wada
  • ,
  • Érica T Prates
  • ,
  • Ryo Hirano
  • ,
  • Allison Z Werner
  • ,
  • Naofumi Kamimura
  • ,
  • Daniel A Jacobson
  • ,
  • Gregg T Beckham
  • ,
  • Eiji Masai

64
開始ページ
167
終了ページ
179
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.ymben.2021.01.013

Pseudomonas putida KT2440 (hereafter KT2440) is a well-studied platform bacterium for the production of industrially valuable chemicals from heterogeneous mixtures of aromatic compounds obtained from lignin depolymerization. KT2440 can grow on lignin-related monomers, such as ferulate (FA), 4-coumarate (4CA), vanillate (VA), 4-hydroxybenzoate (4HBA), and protocatechuate (PCA). Genes associated with their catabolism are known, but knowledge about the uptake systems remains limited. In this work, we studied the KT2440 transporters of lignin-related monomers and their substrate selectivity. Based on the inhibition by protonophores, we focused on five genes encoding aromatic acid/H+ symporter family transporters categorized into major facilitator superfamily that uses the proton motive force. The mutants of PP_1376 (pcaK) and PP_3349 (hcnK) exhibited significantly reduced growth on PCA/4HBA and FA/4CA, respectively, while no change was observed on VA for any of the five gene mutants. At pH 9.0, the conversion of these compounds by hcnK mutant (FA/4CA) and vanK mutant (VA) was dramatically reduced, revealing that these transporters are crucial for the uptake of the anionic substrates at high pH. Uptake assays using 14C-labeled substrates in Escherichia coli and biosensor-based assays confirmed that PcaK, HcnK, and VanK have ability to take up PCA, FA/4CA, and VA/PCA, respectively. Additionally, analyses of the predicted protein structures suggest that the size and hydropathic properties of the substrate-binding sites of these transporters determine their substrate preferences. Overall, this study reveals that at physiological pH, PcaK and HcnK have a major role in the uptake of PCA/4HBA and FA/4CA, respectively, and VanK is a VA/PCA transporter. This information can contribute to the engineering of strains for the efficient conversion of lignin-related monomers to value-added chemicals.

リンク情報
DOI
https://doi.org/10.1016/j.ymben.2021.01.013
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/33549838
ID情報
  • DOI : 10.1016/j.ymben.2021.01.013
  • ORCIDのPut Code : 88190489
  • PubMed ID : 33549838

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