Isolation of threonyl adenylate-enzyme complex

Abstract

The aminoacyl-RNA synthetases have been shown to carry out the following two-step reaction: 1. 1) amino acid + ATP + enzyme ⇌ aminoacyl-AMP-enzyme + PPi 2. 2) aminoacyl-AMP-enzyme + sRNA ⇌ aminoacyl-sRNA + AMP + enzyme. Evidence for the formation of the intermediate aminoacyl-AMP-enzyme complex has been reported by several investigators (Hoagland, 1955, De Moss and Novelli, 1955, Berg, 1956). Tryptophanyl adenylate (Karasek, et, al., 1958) and seryl adenylate (Webster and Davie, 1961) were isolated in trichloroacetic acid supernatant fractions after incubation of amino acid and ATP with substrate amounts of the respective enzymes. The present communication describes the isolation of enzyme-bound threonyl adenylate and the capacity of this complex to transfer the threonine directly to sRNA. © 1964.