[Factors controlling the biosynthesis of chlorosome antenna bacteriochlorophylls in green filamentous anoxygenic phototrophic bacteria of the family Oscillochloridaceae].
We determined the concentrations of bacteriochlorophylls (BChl) in the light-harvesting antennae of Oscillochloris trichoides (of the family Oscillochloridaceae belonging to green filamentous mesophilic bacteria) cultivated either with gabaculine, an inhibitor of the C-5 pathway of BChl biosynthesis in a number of bacteria, or at various illumination intensities. We determined the BChl c: BChl a molar ratios in intact cells, in chlorosome-membrane complexes, and in isolated chlorosomes. We revealed that BChl c synthesis in Osc. trichoides was more gabaculine-sensitive than BChl a synthesis. Accordingly, an increase in gabaculine concentrations in the medium resulted in a decrease in the BChl c: BChl a ratio in the tested samples. We suggest that BChl synthesis in Osc. trichoides proceeds via the C-5 pathway, similar to representatives of other families of green bacteria (Chlorobium limicola and Chloroflexus aurantiacus). We demonstrated that the BChl c: BChl a ratio in the chlorosomes varied from 55 : 1 to 110 : 1, depending on light intensity. This ratio is, therefore, closer to that of Chlorobiaceae, and it significantly exceeds the BChl c: BChl a ratio in Chloroflexaceae.
Taisova
A S
AS
Keppen
O I
OI
Novikov
A A
AA
Naumova
A A
AA
Fetisov
Z G
ZG
D001426:Bacterial Proteins / Q000032:analysis* / Q000378:metabolism; D025541:Bacteriochlorophyll A / Q000032:analysis* / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000032:analysis* / Q000378:metabolism; D041862:Chloroflexi / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism*; D010788:Photosynthesis
D001426:Bacterial Proteins; D025541:Bacteriochlorophyll A; D001429:Bacteriochlorophylls; D003509:Cyclohexanecarboxylic Acids; D004791:Enzyme Inhibitors; D045342:Light-Harvesting Protein Complexes; C012987:gabaculine; C002084:bacteriochlorophyll c