The tRNA thiolation pathway modulates the intracellular redox state in Escherichia coli

Toru Nakayashiki, Natsumi Saito, Rikiya Takeuchi, Hiroshi Kadokura, Kenji Nakahigashi, Barry L. Wanner, Hirotada Mori

研究成果: Article査読

13 被引用数 (Scopus)

抄録

We have performed a screening of hydroxyurea (HU)-sensitive mutants using a single-gene-deletion mutant collection in Escherichia coli K-12. HU inhibits ribonucleotide reductase (RNR), an enzyme that catalyzes the formation of deoxyribonucleotides. Unexpectedly, seven of the mutants lacked genes that are required for the incorporation of sulfur into a specific tRNA modification base, 5-methylaminomethyl-2-thiouridine (mnm5s2U), via persulfide relay. We found that the expression of RNR in the mutants was reduced to about one-third both in the absence and presence of HU, while sufficient deoxynucleoside triphosphate (dNTP) was maintained in the mutants in the absence of HU but a shortage occurred in the presence of HU. Trans-supply of an RNR R2 subunit rescued the HU sensitivity of these mutants. The mutants showed high intracellular ATP/ADP ratios, and overexpression of Hda, which catalyzes the conversion of DnaA-ATP to DnaA-ADP, rescued the HU sensitivity of the mutants, suggesting that DnaA-ATP represses RNR expression. The high intracellular ATP/ADP ratios were due to high respiration activity in the mutants. Our data suggested that intracellular redox was inclined toward the reduced state in these mutants, which may explain a change in RNR activity by reduction of the catalytically formed disulfide bond and high respiration activity by the NADH reducing potential. The relation between persulfide relay and intracellular redox is discussed.

本文言語English
ページ(範囲)2039-2049
ページ数11
ジャーナルJournal of bacteriology
195
9
DOI
出版ステータスPublished - 2013 5
外部発表はい

ASJC Scopus subject areas

  • 微生物学
  • 分子生物学

フィンガープリント

「The tRNA thiolation pathway modulates the intracellular redox state in Escherichia coli」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル