Format

Send to

Choose Destination
FEBS Lett. 2003 Nov 27;555(1):45-50.

Proton transfer pathways and mechanism in bacterial reaction centers.

Author information

1
Department of Physics 0319, University of California San Diego, La Jolla, CA 92093, USA.

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 QB to quinol QBH2 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 10(5) 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.

PMID:
14630317
DOI:
10.1016/s0014-5793(03)01149-9
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center