In:
FEBS Letters, Wiley, Vol. 555, No. 1 ( 2003-11-27), p. 45-50
Abstract:
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. Zn 2+ and Cd 2+ ); (2) the rate constants for proton transfer, obtained from a ‘chemical rescue’ study was determined to be 2×10 5 s −1 and 2×10 4 s −1 for the proton uptake to Glu‐L212 and Q B − , 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.
Type of Medium:
Online Resource
ISSN:
0014-5793
,
1873-3468
DOI:
10.1016/S0014-5793(03)01149-9
Language:
English
Publisher:
Wiley
Publication Date:
2003
detail.hit.zdb_id:
1460391-3
SSG:
12
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