Growth phase-dependent expression and degradation of histones in the thermophilic archaeon Thermococcus zilligii

The majority of cells in nature probably exist in a stationary-phase-like state, due to nutrient limitation in most environments. Studies on bacteria and yeast reveal morphological and physiological changes throughout the stationary phase, which lead to an increased ability to survive prolonged nutrient limitation. However, there is little information on archaeal stationary phase responses. We investigated protein- and lipid-level changes in Thermococcus kodakarensis with extended time in the stationary phase. Adaptations to time in stationary phase included increased proportion of membrane lipids with a tetraether backbone, synthesis of proteins that ensure translational fidelity, specific regulation of ABC transporters (upregulation of some, downregulation of others), and upregulation of proteins involved in coenzyme production. Given that the biological mechanism of tetraether synthesis is unknown, we also considered whether any of the protein-level changes in T. kodakarensis might shed light on the production of tetraether lipids across the same period. A putative carbon-nitrogen hydrolase, a TldE (a protease in Escherichia coli) homologue, and a membrane bound hydrogenase complex subunit were candidates for possible involvement in tetraether-related reactions, while upregulation of adenosylcobalamin synthesis proteins might lend support to a possible radical mechanism as a trigger for tetraether synthesis

19th international isotope society (UK group) symposium: synthesis & applications of labelled compounds 2010

The 19th annual symposium of the International Isotope Society’s United Kingdom Group took place at the Wellcome Genome Campus, Hinxton, Cambridge, UK on Thursday 14th October 2010. The meeting was attended by around 80 delegates from academia and industry, the life sciences, chemical, radiochemical and scientific instrument suppliers.The Harrowven contribution:Since Kekule ? first proposed his ouroboros-inspired structure for benzene in the mid-nineteenth century, it has been regarded as the archetypal aromatic compound – flat, with carbon-carbon bonds of equal length and bond angle.1 The viability of non-planar benzene rings has been known for many decades, with the first reported example of a boat-configured arene dating to the synthesis of [2.2]paracyclophane in 1949.2 However, it was arguably the isolation of (1)-cavicularin in 1996, and latterly of the haouamines and hirsutellones, that alerted the wider scientific community to the existence of biosynthetic pathways for the generation of such motifs in Nature (Figure 1).Through a combination of chemical synthesis (cavicularin,3,4 riccardin C3,4 and RP-664534), molecular modelling and data mining, we have strong evidence to suggest that boat-configured arenes are far more common in natural products than has been traditionally thought, spanning many classes including macrocyclic alkaloids, guaianolides, bisbibenzyls, peptides and biarylheptanoids. In addition, our work provides guidance for addressing the chemical synthesis of such targets