NUCLEOTIDE-SEQUENCES OF GENES-CODING FOR PHOTOSYNTHETIC REACTION CENTERS AND LIGHT-HARVESTING PROTEINS OF ACIDIPHILIUM-RUBRUM AND RELATED AEROBIC ACIDOPHILIC BACTERIA
Kvp. Nagashima et al., NUCLEOTIDE-SEQUENCES OF GENES-CODING FOR PHOTOSYNTHETIC REACTION CENTERS AND LIGHT-HARVESTING PROTEINS OF ACIDIPHILIUM-RUBRUM AND RELATED AEROBIC ACIDOPHILIC BACTERIA, Plant and Cell Physiology, 38(11), 1997, pp. 1249-1258
The nucleotide sequences of the puf operons of the Zn-bacteriochloroph
yll a (Zn-BChl a)-containing photosynthetic aerobic bacteria, Acidiphi
lium rubrum and Acidiphilium angustum, were determined. The nucleotide
sequences of the pufL and -M of Acidiphilium cryptum, Acidiphilium mu
ltivorum, and Acidiphilium organovorum were also determined. The puf o
perons of A. rubrum and A. angustum contained pufB, -A, -L, -M, and -C
as seen in other purple bacteria with an unknown gene directly upstre
am of pufB, Comparing the deduced amino acid sequences of the puf gene
s of the Acidiphilium species with those of other purple bacteria show
ed that His L168, which is highly conserved in other bacteria, is repl
aced by a glutamic acid in the Acidiphilium species. The three-dimensi
onal structures of the reaction centers of Blastochloris (Rhodopseudom
onas) viridis and Rhodobacter sphaeroides suggest that this residue lo
cates closely to a special pair of bacteriochlorophylls and may be inv
olved in the stabilization and function of ''Zn-BChl a''. The relative
content of charged amino acid residues in the L and M subunit is a li
ttle lower in A. rubrum (10% of total) than in B. viridis (12%), and t
he tendency is more pronounced in the cytochrome subunit: 12.5% in A.
rubrum and 18.8% in B. viridis.