A protein conformational change associated with the photoreduction of the primary and secondary quinones in the bacterial reaction center

FEBS Letters

Nabedryk, E.¹  Thibodeau, D.L.¹  Bauscher, M.³  Breton, J.¹  Mäntele, W.³  Bagley, K.A.² 

[1]Service de Biophysique, C.E.N. Saclay, 91191 Gif-sur-Yvette cedex, France

[2]Department of Physics, University of California at San Diego, La Jolla, CA 92093, USA

[3]Institut für Biophysik und Strahlenbiologie, Albertstr. 23, 7800 Freiburg, FRG

关键词: Fourier transform infrared spectroscopy;    Bacterial reaction center;    Photosynthesis;    Primary quinone;    Secondary quinone;    FTIR;    Fourier transform infrared;    QA (QB);    primary (secondary) quinone;    P;    primary electron donor;    BChl;    bacteriochlorophyll;    RC;    reaction center;   

DOI  :  10.1016/0014-5793(90)81506-J

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A comparison is made between the PQ_A → P⁺Q⁻ _A and PQ_AQ_B → P⁺Q_AQ⁻ _B transitions in Rps. viridis and Rb. sphaeroides reaction centers (RCs) by the use of light-induced Fourier transform infrared (FTIR) difference spectroscopy. In Rb. sphaeroides RCs, we identify a signal at 1650 cm⁻¹ which is present in the P⁺Q_A-minus-PQ_A spectrum and not in the P⁺Q_AQ⁻ _B-minus-PQ_AQ_B spectrum. In contrast, this signal is present in both P⁺Q⁻ _A-minus-PQ⁻ _A and P⁺Q_AQ⁻ _B-minus-PQ_AQ_B spectra of Rps. viridis RCs. These data are interpreted in terms of a conformational change of the protein backbone near Q_A (possible at the peptide C≡O of a conserved alanine residue in the Q_A pocket) and of the different bonding interactions of Q_B with the protein in the RC of the two species.

【 授权许可】

Unknown