Department of Biochemistry and Molecular Pharmacology
*Base Sequence; Coliphages; *DNA Mutational Analysis; Methylnitronitrosoguanidine; *Mutation; *Streptozocin; Tetracycline Resistance
Life Sciences | Medicine and Health Sciences
The isolation and characterization of streptozotocin (STZ)-induced mutations in the phage P22 mnt repressor gene is described. Cells carrying the plasmid-borne mnt gene were exposed to STZ to give 10-20 percent survival and at least an eleven-fold increase in mutation frequency. DNA sequence analysis showed that 50 of 51 STZ-induced mutations were GC to AT transitions, and one was an AT to GC transition. We have also compared the STZ mutational spectrum to that for N-methyl-N'-nitro-N-nitroso-guanidine (MNNG). There are sites in the mnt gene which are mutated only by STZ; only by MNNG, or by both agents. Sites at which only STZ induced GC to AT transition mutations occur were in sequences that are pyrimidine rich 5' to the mutated site and purine rich 3' to the mutated site. Induction of mutations by both STZ and MNNG should be considered to maximize the number of mutable sites.
DOI of Published Version
Nucleic Acids Res. 1988 Oct 25;16(20):9811-20. Link to article on publisher's website
Nucleic acids research
Mack, Susan L.; Fram, Robert J.; and Marinus, Martin G., "Sequence specificity of streptozotocin-induced mutations" (1988). Open Access Articles. 1713.