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Updated: Aug 13, 2026

Isolation of Translating Ribosomes Containing Peptidyl-tRNAs for Functional and Structural Analyses
Published on: February 25, 2011
Peptidyl-puromycin synthesis on polyribosomes from Escherichia coli
Abstract:
Peptide bond synthesis was studied with native polyribosomes of E. coli. With the use of this system for transpeptidation, it was possible to show that a single K(+) activates the ribosome monomers of polyribosomes; that protonation of a single group (probably imidazole or an N-terminal amino group) with a pK(a) equal to about 7.2 inactivates the transpeptidase complex; that Mn(++) can substitute for Mg(++), but that Ca(++), spermidine, and putrescine do so only very poorly; and that the K(m) for puromycin in this system is about 2.4 x 10(-6) M.
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