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

Autor: Nabedryk, E., Bagley, K.A., Thibodeau, D.L., Bauscher, M., Mäntele, W., Breton, J.
Zdroj: FEBS Letters; January 1990, Vol. 266 Issue: 1 p59-62, 4p
Abstrakt: A comparison is made between the PQ A→ P +Q −Aand PQ AQ B→ P +Q AQ −Btransitions in Rps. viridisand Rb. sphaeroidesreaction centers (RCs) by the use of light-induced Fourier transform infrared (FTIR) difference spectroscopy. In Rb. sphaeroidesRCs, we identify a signal at 1650 cm −1which is present in the P +Q A-minus-PQ Aspectrum and not in the P +Q AQ −B-minus-PQ AQ Bspectrum. In contrast, this signal is present in both P +Q −A-minus-PQ −Aand P +Q AQ −B-minus-PQ AQ Bspectra of Rps. viridisRCs. 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 Apocket) and of the different bonding interactions of Q Bwith the protein in the RC of the two species.
Databáze: Supplemental Index
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