BIOSYNTHESIS OF RIBOSE AND DEOXYRIBOSE IN PSEUDOMONAS SACCHAROPHILA

Abstract

The biosynthesis of ribose and deoxyribose in Pseudomonas saccharophila was studied by radioisotope-tracer techniques. Patterns of C14 in ribose isolated from the nucleic acids of cells grown on labeled glucose suggested that pentose was made by the pathway involving transaldolase and transketolase. When cells were grown on radioactive gluconate, the tracer patterns indicated the possibility of a new pathway for the biosynthesis of ribose. Isotopic patterns in deoxyribose, in general, were consistent with the pathway involving reduction of ribonucleotides to deoxyribonucleotides. Certain aspects of the data, however, were not explained by this known pathway.

Biosynthesis of deoxyribose in wheat embryos

“…Glucose-6-1 'C Feeding Experiments. Of the four possible metabolic pathways of deoxyribose biosynthesis previously discussed, the condensation of acetaldehyde and glyceraldehyde 3-phosphate by the enzyme deoxyribose phosphate aldolase has received little support in that the enzyme affinity for acetaldehyde is too low to form any significant amount of product in vivo (Wright et al, 1961;Fossitt and Bernstein, 1963; Ghosh and Bernstein, 1963;Hammersten et al, 1950). The glucuronic acid-xylulose cycle appears to be relatively unimportant for the biosynthesis of deoxyribose and ribose, at least in animals (Hiatt and Lareau, 1958).…”