Molecular Pharmacology, Vol 15, 691-697, Copyright © 1979 by the American Society for Pharmacology and Experimental Therapeutics

Action of 3-Deazaguanine in Escherichia coli

¹ Department of Developmental Therapeutics, The University of Texas System Cancer Center, M. D. Anderson Hospital and Tumor Institute, Houston, Texas 77030

3-Deazaguanine is more inhibitory to E. coli B3 than purine analogues such as 8-azaguanine and 8-azaadenine, as measured by growth and viability. It inhibits DNA synthesis with little effect on RNA formation and results in aberrant morphology. Inhibition can be reversed or prevented by the presence of adenine or guanine during exposure to drug. A 3-deazaguanine resistant strain was isolated and found to be deficient in guanine phosphoribosyltransferase activity. The parent strain, E. coli B3, is slightly sensitive to 3-deazaguanosine but highly sensitive to 7-ribosyl-3-deazaguanine. The 3-deazaguanine resistant strain is completely resistant to both nucleosides.

Note:
ACKNOWLEDGMENT The authors are indebted to Dr. Frances Arrighi for assistance in obtaining the photographs of Figure 2.