Azaserine: survival and mutation in Escherichia coli.

Azaserine in an antineoplastic agent, mutagen and carcinogen that is known to inhibit purine metabolism. Comparison of mutation in stationary-phase cultures of E. coli WP2 and a series of its DNA repair-deficient mutants exposed to azaserine showed that the effects of the compound closely mimicked those caused by UV light indicating, therefore, that azaserine-induced mutagenesis occurred via pathways dependent upon the recA and lexA genes. Comparison of survival of these strains showed that potentially lethal DNA lesions induced by azaserine were corrected by the excision, recombination, and rec-lex repair systems. These results show that azaserine causes DNa damage as well as inhibition of purine metabolism.