ubiJ, a New Gene Required for Aerobic Growth and Proliferation in Macrophage, Is Involved in Coenzyme Q Biosynthesis in Escherichia coli and Salmonella enterica Serovar Typhimurium

作者：Aussel Laurent; Loiseau Laurent; Chehade Mahmoud Hajj; Pocachard Berengere; Fontecave Marc; Pierrel Fabien; Barras Frederic^*

来源：Journal of Bacteriology, 2014, 196(1): 70-79.

DOI：10.1128/JB.01065-13

Ubiquinone (coenzyme Q or Q(8)) is a redox active lipid which functions in the respiratory electron transport chain and plays a crucial role in energy-generating processes. In both Escherichia coli and Salmonella enterica serovar Typhimurium, the yigP gene is located between ubiE and ubiB, all three being likely to constitute an operon. In this work, we showed that the uncharacterized yigP gene was involved in Q(8) biosynthesis in both strains, and we have renamed it ubiJ. Under aerobic conditions, an ubiJ mutant was found to be impaired for Q(8) biosynthesis and for growth in rich medium but did not present any defect anaerobically. Surprisingly, the C-terminal 50 amino acids, predicted to interact with lipids, were sufficient to restore Q(8) biosynthesis and growth of the ubiJ mutant. Salmonella ubiE and ubiB mutants were impaired in Q(8) biosynthesis and in respiration using different electron acceptors. Moreover, ubiE, ubiJ, and ubiB mutants were all impaired for Salmonella intracellular proliferation in macrophages. Taken together, our data establish an important role for UbiJ in Q(8) biosynthesis and reveal an unexpected link between Q(8) and virulence. They also emphasize that Salmonella organisms in an intracellular lifestyle rely on aerobic respiration to survive and proliferate within macrophages.

• 出版日期2014-1
• 单位中国地震局