THE TURNOVER OF RIBONUCLEIC ACIDS THEIR DEGRADATION BY CHARACTERISTIC ENZYMIC PATHWAYS IN ESCHERICHIA COLI

Abstract

To elucidate the mechanism of turnover of RNA, enzymes related to the complete degradation of RNA molecules in the cells of Escherichia coli were studied and theoretically possible systems for their action were reconstructed.A hypotherical model of these enzyme systems was proposed with two distinct pathways for RNA degradation with subsequent re-utilization of the resulting materials. These pathways are the RNase I pathway and the PNPase-RNase II pathway. Some experimental evidence showing that this model system is actually working in vivo was given and possible mechanisms for the regulation of the pathways were discussed.
Based on the present hypothesis, the sense of the phenomenon of turnover used hitherto was reconsidered and molecular aspects of the turnover of RNA were presented in a new light.