Range: ±2 µM
||Bacteria Escherichia coli
||Jewett MC, Miller ML, Chen Y, Swartz JR. Continued protein synthesis at low [ATP] and [GTP] enables cell adaptation during energy limitation.J Bacteriol. 2009 Feb191(3):1083-91PubMed ID19028899
||To measure the dependence of the protein synthesis rate on [ATP] and [GTP], researchers used an in vitro cell-free system derived from E. coli extracts. Cell-free systems provide the opportunity to directly monitor, add, and remove components with much greater ease and accuracy than can be done with in vivo systems.
||Researchers used an integrated Escherichia coli cell-free platform that mimics the intracellular, energy-limited environment to show that protein synthesis rates are governed by simple Michaelis-Menten dependence on [ATP] and [GTP] (K(m)(ATP), 27 +/- 4 microM, BNID (104731) K(m)(GTP), 14 +/- 2 microM). Although the ATP concentration is probably the single most important parameter influencing the entire protein synthesis system, GTP is required for translation initiation, for elongation, and for termination.