Flash‐induced electrogenic reactions in the SA(L223) reaction center mutant in Rhodobacter sphaeroides chromatophores
Open Access
- 14 March 1994
- journal article
- Published by Wiley in FEBS Letters
- Vol. 341 (1), 10-14
- https://doi.org/10.1016/0014-5793(94)80230-0
Abstract
The charge transfer events in the SA(L223) reaction center mutant Rhodobacter sphaeroides chromatophores were investigated by direct electrometry. Besides the primary charge separation, the small stigmatellin‐sensitive electrogenic reaction due to the electron transfer from the primary to the secondary quinone acceptor in the reaction center complex was observed after the first flash. The second flash‐induced electrogenic phase of the secondary quinone protonation and subsequent electrogenic reactions of the cytochrome bc 1 complex were much slower than those in chromatophores of the wild type. It is suggested that replacement of Ser‐L223 by Ala impairs both specific proton‐conducting pathways leading to the secondary quinone QB.Keywords
This publication has 18 references indexed in Scilit:
- Flash-induced electric potential generation in wild type and L212EQ mutant chromatophores of Rhodobacter sphaeroides: QBH2 is not released from L212EQ mutant reaction centersBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1993
- PROTON TRANSFER IN REACTION CENTERS FROM PHOTOSYNTHETIC BACTERIAAnnual Review of Biochemistry, 1992
- Proton and electron transfer in the acceptor quinone complex of Rhodobacter sphaeroides reaction centers: characterization of site-directed mutants of the two ionizable residues, GluL212 and AspL213, in the QB binding siteBiochemistry, 1992
- A crucial role for AspL213 in the proton transfer pathway to the secondary quinone of reaction centers from Rhodobacter sphaeroidesBiochimica et Biophysica Acta (BBA) - Bioenergetics, 1990
- Pathway of proton transfer in bacterial reaction centers: replacement of serine-L223 by alanine inhibits electron and proton transfers associated with reduction of quinone to dihydroquinone.Proceedings of the National Academy of Sciences, 1990
- Electrogenesis associated with proton transfer in the reaction center protein of the purple bacterium Rhodobacter sphaeroidesFEBS Letters, 1990
- Pathway of proton transfer in bacterial reaction centers: replacement of glutamic acid 212 in the L subunit by glutamine inhibits quinone (secondary acceptor) turnover.Proceedings of the National Academy of Sciences, 1989
- Efficient oligonucleotide-directed construction of mutations in expression vectors by the gapped duplex DNA method using alternating selectable markersNucleic Acids Research, 1989
- Structure of the reaction center from Rhodobacter sphaeroides R-26: protein-cofactor (quinones and Fe2+) interactions.Proceedings of the National Academy of Sciences, 1988
- Electrogenic reduction of the secondary quinone acceptor in chromatophores of Rhodospirillum rubrumFEBS Letters, 1986