Nature, Volume 510 number 7505
The metabolite α-ketoglutarate extends lifespan by inhibiting ATP synthase and TOR
It has been known that metabolism is related to lifespan. In this paper, authors identified that α-ketoglutarate (αKG), a tricarboxylic acid cycle intermediate, is involved in extension of the lifespan of adult Caenorhabditis elegans. According to this paper, it seems that life is extended by reduced activity of ATPase due to a binding to αG. This result suggests some strategies for the prevention and treatment of ageing and age-related diseases such as dietary restriction or absorption of αG with some constant doze.
MurJ is the flippase of lipid-linked precursors for peptidoglycan biogenesis.
In this paper, authors confirm that MurJ is the flippase of lipid precursor. They also find that Alanine at 29 is responsible for lipid translocation. MTSES is used to labeled to the Cysteine whom Alanine at 29 was replaced with. In the presence of MTSES, the activity of MurJ is suppressed in the mutant. However, the function of mutant MurJ is same to that of wild type in the absence of MTSES. These biochemical results easily and clearly unravel the mysterious cover of MurJ.
PNAS. Vol. 111, No. 19
Trapped translocation intermediates establish the route for export of capsular polysaccharides across Escherichia coli outer membranes.
Protein secretion in the bacteria is always hot topic, since understanding the mechanism of secretion is helpful for designing anti-bacterial strategies. In this paper, the authors focus on one protein named Wza, locating at outer membrane of E. coli. This protein is working for exporting outer membrane polysaccharides. They used the UV photo-cross-linkable unnatural amino acid p-benzoyl-L-phenylalanine to trap several intermediates of Wza with polysaccharides so as to capture different phases of exporting when polysaccharides are trafficking through the export pathway.