PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 3058202-3 1988 We have used electron paramagnetic resonance spectroscopy to investigate the pathway of photooxidation of cytochrome b-559 in PSII and have shown that it proceeds via photooxidation of chlorophyll. Chlorophyll 185-196 mitochondrially encoded cytochrome b Homo sapiens 106-118 3058202-6 1988 We propose that the function of cytochrome b-559 is to mediate cyclic electron transfer to rereduce photooxidized chlorophyll and protect PSII from photoinhibition. Chlorophyll 114-125 mitochondrially encoded cytochrome b Homo sapiens 32-44