Open AccessEfficient excision of phage lambda from the Escherichia coli chromosome requires the Fis protein
Author(s) -
Catherine A. Ball,
Reid C. Johnson
Publication year - 1991
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.173.13.4027-4031.1991
Subject(s) - lysogen , biology , recombination , lambda phage , lytic cycle , bacteriophage , escherichia coli , microbiology and biotechnology , lysogenic cycle , mutant , homologous recombination , genetics , dna , virus , gene
The Escherichia coli protein Fis has been shown to bind a single site in the recombination region of phage lambda and to stimulate excisive recombination in vitro (J. F. Thompson, L. Moitoso de Vargas, C. Koch, R. Kahmann, and A. Landy, Cell 50:901-908, 1987). We demonstrate that mutant strains deficient in fis expression show dramatically reduced rates of lambda excision in vivo. Phage yields after induction of a stable lysogen are reduced more than 200-fold in fis cells. The defect observed in phage yield is not due to inefficient phage replication or lytic growth. Direct examination of excisive recombination products reveals a severe defect in the rate of recombination in the absence of Fis. The excision defect observed in fis cells can be fully reproduced in fis+ cells by using phages that lack the Fis binding site on attR, indicating that the entire stimulatory effect of Fis on excisive recombination is due to binding at that site.