The secondary electron acceptor of photosystem I in Gloeobacter violaceus PCC 7421 is menaquinone-4 that is synthesized by a unique but unknown pathway

FEBS Lett. 2005 Jul 4;579(17):3493-6. doi: 10.1016/j.febslet.2005.05.029.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Chlorophyll / analogs & derivatives
  • Chlorophyll / analysis
  • Cyanobacteria / chemistry
  • Cyanobacteria / genetics
  • Cyanobacteria / metabolism*
  • Genome, Bacterial
  • Naphthols / metabolism
  • Photosystem I Protein Complex / genetics
  • Photosystem I Protein Complex / metabolism*
  • Vitamin K 1 / analysis
  • Vitamin K 1 / metabolism
  • Vitamin K 2 / analogs & derivatives*
  • Vitamin K 2 / analysis
  • Vitamin K 2 / metabolism

Substances

  • Naphthols
  • Photosystem I Protein Complex
  • Vitamin K 2
  • Chlorophyll
  • 1,4-dihydroxy-2-naphthoic acid
  • chlorophyll a'
  • menatetrenone
  • Vitamin K 1