Dependence of education on P2 int product

Abstract

When temperate phage P2 is established as prophage at a chromosomal site near the histidine operon (location H) in Escherichia coli, it generates nonlysogenic segregants which are deleted for the his genes and several other host genes ( Sunshine and Kelly, 1971; Kelly and Sunshine, 1967). This phenomenon, termed “education,” is dependent on the presence of the P2 prophage (structural requirement) and on the production of P2 int gene product. A P2 gene required for normal prophage excision ( cox) is not required for education, and the recA + function of the host is not involved. The frequency of eduction can be increased by supplying int product through homoimmune superinfection. A temperature-inducible P2 mutant (P2 c 5 nip 1) causes eduction at elevated levels when established as prophage at location H. This finding suggests that lysogens of this mutant contain high levels of P2 int product.