Bacterial Synthesis of Nucleotides

Part V. Acceptor Specificity of Nucleoside Phosphotransferase (I): Phosphorylation of Ribonucleosides

Abstract

1) Various kinds of naturally occurring ribonucleosides were found to be phosphory-lated by bacterial nucleoside phosphotrans-ferases using p-NPP as a phosphate donor at pH 4.0.
2) Nucleotide-isomers synthesized are not always the same, but some bacteria belonging to genera Pseudomonas, Flavobacterium, Serratia and Staphylococcus were characterized to synthesize mainly 5'-isomer, whereas the others belonging to genera Aeromonas, Escherichia, Aerobacter and Proteus to phosphorylate preferably at C₃', and C_2', without distinction of purine or pyrimidine ribonu-cleosides.
3) The ratio of 3' and 2'-isomer synthesized by the latter group of bacteria may be observed to be different; 3'-isomer seems to be preferentially synhtesized in the case of purine ribonucleoside, while 3'-isomer seems to be less than 2'-isomer in the synthesis of pyrimidine ribonucleotides.
4) The cause of difference present between the synthesis of 2' and 3'-isomer by the latter group was discussed.