2N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia; fax: +7 (499) 137-8357
* To whom correspondence should be addressed.
Received January 27, 2015; Revision received March 8, 2015
The pigment–protein complex of photosystem I (PS I) catalyzes light-driven oxidation of plastocyanin or cytochrome c6 and reduction of ferredoxin or flavodoxin in oxygenic photosynthetic organisms. In this review, we describe the current state of knowledge of the processes of excitation energy transfer and formation of the primary and secondary ion-radical pairs within PS I. The electron transfer reaction involving quinone cofactor in the A1 site and its role in providing asymmetry of electron transport as well as interaction with oxygen and ascorbate in PS I are discussed.
KEY WORDS: photosystem I, reaction center, electron transfer, asymmetry, primary reactions, quinone acceptors, interaction with oxygen and ascorbate