SHORTCUT OF THE PHOTOSYNTHETIC ELECTRON-TRANSFER IN A MUTANT LACKING THE REACTION CENTER-BOUND CYTOCHROME SUBUNIT BY GENE DISRUPTION IN A PURPLE BACTERIUM, RUBRIVIVAX-GELATINOSUS
Kvp. Nagashima et al., SHORTCUT OF THE PHOTOSYNTHETIC ELECTRON-TRANSFER IN A MUTANT LACKING THE REACTION CENTER-BOUND CYTOCHROME SUBUNIT BY GENE DISRUPTION IN A PURPLE BACTERIUM, RUBRIVIVAX-GELATINOSUS, FEBS letters, 385(3), 1996, pp. 209-213
A mutant lacking the reaction center-bound cytochrome subunit was cons
tructed in a purple photosynthetic bacterium, Rubrivivax gelatinosus I
L144, by inactivation of the cytochrome gene, Photosynthetic growth of
the C244 mutant strain occurred at approximately half the rate of the
wild-type strain, Although mutagenesis resulted in a greatly reduced
amount of membrane-bound cytochromes c, illumination induced cyclic el
ectron transfer and the generation of membrane potential in the mutant
as observed in the wild-type strain, These findings are consistent wi
th previous observations that the cytochrome subunit is absent in the
reaction center complex in some species of purple bacteria and that th
e biochemical removal of the subunit did not significantly affect the
in vitro electron transfer from the soluble cytochrome c to the photos
ynthetic reaction center, These results suggest that the cytochrome su
bunit in purple bacteria is not essential for photosynthetic electron
transfer and growth, even in those species generally containing the su
bunit.