Membrane Lipid Biosynthesis in Purple Bacteria

摘要: Membranes are essential to all living cells. They provide the boundary surrounding environment, allow controlled exchange of compounds through membrane transporters, and serve as a matrix for associated enzymes protein complexes involved in generation energy or communication with environment. Biomembranes built from amphipathic, polar lipids that either on their own mixtures other spontaneously form bilayer aqueous solutions. Proteins embedded into this lipid serving many different functions. Photosynthetic purple bacteria have very rich complement including phospholipids not commonly found such phosphatidylcholine, glycolipids typical plant chloroplasts sulfoquinovosyldiacylglycerol, betaine ornithine lipids. These latter lack phosphorus presumably allowing outcompete organisms phosphorusdepleted Advances genetic analysis metabolism related α-proteobacteria group provided us genes encoding biosynthesis beyond those described Escherichia (E.) coli. Lipid discovered first Rhodobacter (Rba.) sphaeroides include sqd required sulfoquinovosyldiacylglycerol bta biosynthesis. Similar approaches closely bacterium Sinorhizobium (Sr.) meliloti combination genome comparison proteins new pathway phosphatidylcholine gave insights specific interactions these complexes.