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The secondary electron acceptor of photosystem I in Gloeobacter violaceus PCC 7421 is menaquinone‐4 that is synthesized by a unique but unknown pathway
Author(s) -
Mimuro Mamoru,
Tsuchiya Tohru,
Inoue Hidetoshi,
Sakuragi Yumiko,
Itoh Yuka,
Gotoh Takanori,
Miyashita Hideaki,
Bryant Donald A.,
Kobayashi Masami
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.05.029
Subject(s) - photosystem i , p700 , photosystem ii , chemistry , electron acceptor , acceptor , molecule , electron transport chain , photosynthesis , stereochemistry , biochemistry , organic chemistry , physics , condensed matter physics
The secondary electron acceptor of photosystem (PS) I in the cyanobacterium Gloeobacter violaceus PCC 7421 was identified as menaquinone‐4 (MQ‐4) by comparing high performance liquid chromatograms and absorption spectra with an authentic compound. The MQ‐4 content was estimated to be two molecules per one molecule of chlorophyll (Chl) a ′, a constituent of P700. Comparative genomic analyses showed that six of eight men genes, encoding phylloquinone/MQ biosynthetic enzymes, are missing from the G. violaceus genome. Since G. violaceus clearly synthesizes MQ‐4, the combined results indicate that this cyanobacterium must have a novel pathway for the synthesis of 1,4‐dihydroxy‐2‐naphthoic acid.