Functional inactivation rates of the messenger RNA molecules coding for the individual ribosomal proteins of Eschrichia coli

Abstract

The rates of functional decay of messenger RNA coding for total soluble, total ribosomal and individual ribosomal proteins were measured in Escherichia coli strain AS-19, at 30o. This was accomplished by blocking RNA synthesis with the inhibitor thiolutin and measuring residual protein synthesis at various times thereafter. The data obtained expressed as a decay constant (Hartwell and Magasanik, 1963) show that both total soluble and total ribosomal protein decay with similar rates (K2=0.64 and 0.61 respectively) which are slightly faster than the decay rate of β-galactosidse (k2=0.43) under these conditions. All the individual ribosomal proteins appear to comprise a population of cistrons whose individual mRNA's decay with very similar rates with the possible exception of protein L3, whose mRNA appears consistently to decay very rapidly.