A novel nucleotide implicated in the response of E. coli to energy source downshift

摘要: When E. coli cells are subjected to energy source downshift, the accumulation of RNA (and overall cell growth) is drastically restricted within 1 2 min. However, identity primary metabolic signal for this adjustment a mystery. Earlier studies, and further evidence presented here, show that there no satisfactory correlation between sudden kinetics changes in levels prospective signalling compounds, such as glycolytic intermediates, ppGpp, ATP, or three adenylate nucleotides. We have discovered an unusual nucleotide, which we call phantom spot, whose level decreases dramatically minute correlating well with accumulation. Preliminary characterization spot indicates it triphosphate derived from guanylate pathway, suggests form GTP modification imidazole portion purine ring. postulate nucleotide serves regulatory facsimile linking rate other anabolic processes phosphorylation.