Modified reaction centres oxidize tyrosine in reactions that mirror photosystem II

L. Kálmán, R. LoBrutto, J. P. Allen () and J. C. Williams
Additional contact information
L. Kálmán: Arizona State University
R. LoBrutto: Arizona State University
J. P. Allen: Arizona State University
J. C. Williams: Arizona State University

Nature, 1999, vol. 402, issue 6762, 696-699

Abstract: Abstract The participation of tyrosine in the oxidation of water by photosystem II, a multisubunit enzyme complex involved in plant photosynthesis, exemplifies the significant role amino-acid side chains play in oxidation/reduction reactions in proteins1. The influence of the surrounding protein on the properties of amino-acid radicals and the attributes necessary for electron transfer are not well understood. Here we report that modifications of reaction centres from the purple bacterium Rhodobacter sphaeroides result in the generation of a tyrosyl radical in a manner similar to that of photosystem II. Our design incorporates a highly oxidizing bacteriochlorophyll dimer possessing a midpoint potential of more than 0.8 V, which was achieved by altering its local environment. After substitution of tyrosine residues at positions corresponding to the tyrosyl radicals of photosystem II, optical and electron paramagnetic resonance spectra showed changes consistent with oxidation of the tyrosine. The properties of this reaction include initiation by light and coupling to proton transfer, most probably to residues near the tyrosines.

Date: 1999
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/45300 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:402:y:1999:i:6762:d:10.1038_45300

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/45300

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().