Enzymic transfer of the ribosyl group from inosine to adenine

Abstract

The formation of radioactive adenosine from (8-C14) adenine and inosine catalyzed by cell-free extracts from Escherichia coli establishes the transfer of the ribosyl group as a mechanism of the reaction. Hypoxanthine formed during the reaction was devoid of radioactivity, a result that eliminates trans-amination as a mechanism. The involvement of ribose 1-phosphate as an intermediate in the reaction and the relationship of the reactions to the deoxyribosyl transfer in Lactobacillus helveticus preparations is discussed.