Original scientific paper

The Possible Roles of Known Enzymes in the Breakdown of RNA in X-Irradiated Escherichia coli

I . Pečevsky ; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
Ž. Kućan ; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia

Abstract

Breafodown of 14C-adenine-labelled RNA of X-irradiated Escherichia
coli proceeds at the same rate in the presence and in the
absence of chloramphenicol, .thus indicating that pre-existing
enzymes are responsible for the process . Though considerable
amounts of RNA are broken down upon the incubation of bacteria
in some salt solutions, the breakdown is e nhanced by irradiation
only when the incubation medium contains both K+ and phosphate.
Nucleoside diphosphates were found among the breakdown products
of 14 C-adenine and 14 -uracil-labelled RNA, together with larger
quantites of nucleoside monophosphates and some tdphosphates.
The radiation-induced breakdown of RNA in a strain lacking
r:ibonuclease I, E. coli MRE 600, proceeds at the same rate as in
E. coli B. On the basis of these and some earlier findings it is
proposed that ribonuclease I does not take part in degradation,
while both ribonuclease II and polynucleotide phosphorylase are
responsible for the process.

Keywords

Hrčak ID:

208045

URI

https://hrcak.srce.hr/208045

Publication date:

25.10.1968.

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