High impact information on Bacterioruberin

• We report here that the binding site confers a chiral geometry on salinixanthin in xanthorhodopsin and confirm that the same is true for bacterioruberin in archaerhodopsin [1].
• In contrast, hydrolysis of the Schiff base in archaerhodopsin does not abolish the CD bands of bacterioruberin [1].
• Retention of the 4-pro-R hydrogen atom of mevalonate at C-2,2' of bacterioruberin in Halobacterium halobium [2].
• We have quantitated transcript levels from these genes in a wild-type and bacterioruberin-deficient mutant of Halobacterium halobium under conditions which affect purple membrane synthesis [3].
• Indeed, transcription was induced, suggesting that the bop gene cluster is not completely uncoupled from regulation by oxygen tension in the bacterioruberin mutant [3].

Biological context of Bacterioruberin

• Three strains of Halobacterium halobium and one of Halobacterium cutirubrum, all of which synthesize purple membrane (Pum+) and bacterioruberin (Rub+), contain plasmids of different size which share extensive sequence homologies [4].
• We show further that despite interaction of bacterioruberin with archaerhodopsin, another retinal-based proton pump, there is no significant energy transfer from this carotenoid [5].

Associations of Bacterioruberin with other chemical compounds

• With this method, we revealed that light enhances the biosynthesis of bacterioruberin and the conversion of beta-carotene to retinal, but does not affect beta-carotene biosynthesis in Halobacterium salinarum strain Oyon Moussa-16 [6].

Analytical, diagnostic and therapeutic context of Bacterioruberin

• Differences are found in the: (1) apparent extinction coefficient of dark/light-adapted aR-2; (2) titration profiles at acidic pH of the absorption spectra of all aRs; and (3) circular dichroism spectra, which are influenced by the coexistent isoprenoid bacterioruberin [7].

References