ISSN:
1617-4623
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Genetically marked λ and P22 phages were recombined in Escherichia coli-Salmonella typhimurium hybrid WR4028, a host sensitive to infection by both of these phages. Hybrid phages that acquired the immC region of P22, but retained the genes for the λ protein coat were selected on WR4027 (λ), a λ-immune, P22-resistant derivative of WR4028. In these λimmP22 hybrids, at least the c through P genes of λ were replaced with functionally related P22 genes. Phage recombinants with more extensive regions of the P22 genome were selected on the double lysogen WR4027 (λ, λimmP22). One such hybrid, λimmP22dis, was determined by heteroduplex analysis to contain approximately 40% of the P22 genome. Genetic studies established that λimmP22dis possesses the two widely separated immunity control regions of P22 (immC and immI) and that these loci are expressed in E. coli K-12 lysogenic for λimmP22dis. In addition, λimmP22dis contains the P22 a1 locus responsible for somatic 0–1 antigen conversion in Salmonella. Although the λimmP22dis phage particle has the λ head and tail, the phage genome also carries P22 tail gene 9 as evidenced by the production of free P22 tails. It also has the P22 att site as indicated by the integration of the λimmP22dis prophage near the proA locus on the bacterial chromosome.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00267614
