Journal
FEBS LETTERS
Volume 555, Issue 1, Pages 45-50Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0014-5793(03)01149-9
Keywords
buffer effect; general acid catalysis; Bronsted plot; proton-coupled electron transfer; hydrogen ion; proton transport; site-directed mutations; bacterial photosynthesis; Rhodobacter sphaeroides
Funding
- NIGMS NIH HHS [GM 41637, GM 13191] Funding Source: Medline
Ask authors/readers for more resources
The focus of this minireview is to discuss the state of knowledge of the pathways and rates of proton transfer in the bacterial reaction center (RC) from Rhodobacter sphaeroides. Protons involved in the light driven catalytic reduction of a quinone molecule Q(B) to quinol Q(B)H(2) travel from the aqueous solution through well defined proton transfer pathways to the oxygen atoms of the quinone. Three main topics are discussed: (1) the pathways for proton transfer involving the residues: His-H126, His-H128, Asp-L210, Asp-M17, Asp-L213, Ser-L223 and Glu-L212, which were determined by a variety of methods including the use of proton uptake inhibiting metal ions (e.g. Zn2+ and Cd2+); (2) the rate constants for proton transfer, obtained from a 'chemical rescue' study was determined to be 2 x 101 s(-1) and 2 x 10(4) s(-1) for the proton uptake to Glu-L212 and QB*, respectively; (3) structural studies of altered proton transfer pathways in revertant RCs that lack the key amino acid Asp-L213 show a series of structural changes that propagate toward L213 potentially allowing Glu-H173 to participate in the proton transfer processes. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available