Uptake and Incorporation of Thymine, Thymidine, Uracil, Uridine, and 5-fluorouracil into the Nucleic Acids of Bacillus Subtilis.

Bodmer, Walter F. (Stanford University School of Medicine, Palo Alto, Calif.), and Susan Grether. Uptake and incorporation of thymine, thymidine, uracil, uridine, and 5-fluorouracil into the nucleic acids of Bacillus subtilis. J. Bacteriol. 89:1011-1014. 1965.-From 55 to 95% of uracil, uridine, or 5-fluorouracil (FU) added to the culture medium is incorporated into the acid-insoluble fraction of cells of Bacillus subtilis strains SB 19 (prototroph) and SB 503 (FU-resistant). Thymine is poorly incorporated (less than 1%); thus, the incorporation of thymidine is limited (less than 12%) by the rapid degradation of the nucleoside to thymine, probably by the enzyme thymidine phosphorylase. Uracil, uridine, and FU were not incorporated into the deoxyribonucleic acid (DNA) of either strain, whereas all the incorporated thymidine was found in the DNA.