Selection for purine regulatory mutants in an E. coli hypoxanthine phosphoribosyl transferase-guanine phosphoribosyl transferase double mutant

Mol Gen Genet. 1981;181(3):313-8. doi: 10.1007/BF00425604.

Abstract

We have studied the relationship betwen purine salvage enzymes, 6-mercaptopurine resistance, and the purR phenotype in E. coli. Mutants resistant to 6-mercaptopurine were found to have defects in HPRT, the purR repressor, or in both. Analysis of these mutants led to the isolation of a hypoxanthine phosphoribosyl transferase-guanine phosphoribosyl transferase double mutant (hpt- gpt-) that is extremely sensitive to adenine. Two classes of adenine resistant mutants were isolated from this strain. The first class was deficient in APRT (apt-) while the second class represented purine regulatory mutants (purR-). There is thus selection for the purR phenotype in a hpt- gpt- background.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenine / pharmacology
  • Adenine Phosphoribosyltransferase / genetics
  • Escherichia coli / genetics*
  • Genes, Regulator*
  • Hypoxanthine Phosphoribosyltransferase / genetics*
  • Mutation
  • Pentosyltransferases / genetics*
  • Purines / metabolism*
  • Selection, Genetic

Substances

  • Purines
  • Pentosyltransferases
  • Adenine Phosphoribosyltransferase
  • Hypoxanthine Phosphoribosyltransferase
  • Adenine