Kvp. Nagashima et al., PHYLOGENETIC ANALYSIS OF PHOTOSYNTHETIC GENES OF RHODOCYCLUS-GELATINOSUS - POSSIBILITY OF HORIZONTAL GENE-TRANSFER IN PURPLE BACTERIA, Photosynthesis research, 36(3), 1993, pp. 185-191
Nucleotide sequences of the genes coding for the M and cytochrome subu
nits of the photosynthetic reaction center of Rhodocyclus gelatinosus,
a purple bacterium in the beta subdivision, were determined. The dedu
ced amino acid sequences of these proteins were compared with those of
other photosynthetic bacteria. Based on the homology of these two pho
tosynthetic proteins, Rc. gelatinosus was placed in the alpha subdivis
ion of purple bacteria, which disagrees with the phylogenetic trees ba
sed on 16S rRNA and soluble cytochrome c2. Horizontal transfer of the
genes which code for the photosynthetic apparatus in purple bacteria c
an be postulated if the phylogenetic trees based on 16S rRNA and solub
le cytochrome c2 reflect the real history of purple bacteria.