論文

査読有り 筆頭著者 責任著者 本文へのリンクあり
2016年1月25日

Mutation-induced perturbation of the special pair P840 in the homodimeric reaction center in green sulfur bacteria

Scientific Reports
  • Chihiro Azai
  • ,
  • Yuko Sano
  • ,
  • Yuki Kato
  • ,
  • Takumi Noguchi
  • ,
  • Hirozo Oh-oka

6
1
開始ページ
19878
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1038/srep19878
出版者・発行元
Springer Science and Business Media LLC

Abstract

Homodimeric photosynthetic reaction centers (RCs) in green sulfur bacteria and heliobacteria are functional homologs of Photosystem (PS) I in oxygenic phototrophs. They show unique features in their electron transfer reactions; however, detailed structural information has not been available so far. We mutated PscA-Leu688 and PscA-Val689 to cysteine residues in the green sulfur bacterium Chlorobaculum tepidum; these residues were predicted to interact with the special pair P840, based on sequence comparison with PS I. Spectroelectrochemical measurements showed that the L688C and V689C mutations altered a near-infrared difference spectrum upon P840 oxidation, as well as the redox potential of P840. Light-induced Fourier transform infrared difference measurements showed that the L688C mutation induced a differential signal of the S-H stretching vibration in the P840+/P840 spectrum, as reported in P800+/P800 difference spectrum in a heliobacterial RC. Spectral changes in the 131-keto C=O region, caused by both mutations, revealed corresponding changes in the electronic structure of P840 and in the hydrogen-bonding interaction at the 131-keto C=O group. These results suggest that there is a common spatial configuration around the special pair sites among type 1 RCs. The data also provided evidence that P840 has a symmetric electronic structure, as expected from a homodimeric RC.

リンク情報
DOI
https://doi.org/10.1038/srep19878 本文へのリンクあり
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000368794000001&DestApp=WOS_CPL
URL
https://www.nature.com/articles/srep19878.pdf
URL
https://www.nature.com/articles/srep19878
ID情報
  • DOI : 10.1038/srep19878
  • ISSN : 2045-2322
  • eISSN : 2045-2322
  • Web of Science ID : WOS:000368794000001

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