Apocytochrome f 320 petA MENRNTFSWVKEQITRSISVSIMIYVITRTSISNAYPIFAQQGYENPREATGRIVCANCHLASKPVDIEVPQAVLPDTVFEAVLRIPYDMQLKQVLANGKKGGLNVGAVLILPEGFELAPPDRISPELKEKIGNLAFQSYRPDKKNILVIGPVPGKKYSEIVFPILSPDPATKKDAHFLKYPIYVGGNRGRGQIYPDGSKSNNTVYNATSTGIVRKILRKEKGGYEISIVDASDGRQVIDIIPPGPELLVSEGESIKIDQPLTSNPNVGGFGQGDAEIVLQDPLRVQGLLFFFASVILAQVFLVLKKKQFEKVQLYEMNF CYF_HORVU Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions (By similarity).