The electron spin echo envelope modulation (ESEEM) spectroscopy is known to be sensitive to the hyperfine and quadrupole interactions of 14N nuclei and is used to probe the nearest surroundings of QA in Zn substituted photosystem II (PSII). The analysis of the ESEEM of the primary acceptor quinone QA has shown the presence of two nitrogen nuclei in its nearest surroundings. The similarity of the acceptor side structures of PSII and bacterial reaction center (RC) is supported by observations of the N ESEEM and the assignment of the nitrogens to the histidine limidazole and to alanine.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics