Break-join recombination in phage lambda.
In phage lambda, when DNA replication is blocked, recombination mediated by the Red pathway occurs only near the double-chain break site, cos, that defines the termini of the virion chromosome. The recombinants initiated by cos contain newly synthesized DNA near cos, in amount corresponding to a few percent of the length of lambda. A restriction enzyme cut delivered to one parent far from cos results in elevated recombination near the restriction site. Recombinants induced by this cut have a similarly small amount of DNA synthesis in these replication-blocked crosses. When restriction cuts are introduced in the presence of normal amounts of all of the DNA replication enzymes, many of the resulting recombinants still enjoy, at most, a small amount of DNA synthesis associated with the exchange event. Thus, these experiments fail to support the previously considered possibility that Red-mediated recombination in lambda proceeds largely through a break-copy pathway.
Stahl
F W
FW
Institute of Molecular Biology, University of Oregon, Eugene 97403-1229.
Fox
M S
MS
Faulds
D
D
Stahl
M M
MM
D010582:Bacteriophage lambda / Q000235:genetics* / Q000378:metabolism; D003433:Crosses, Genetic; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis / Q000378:metabolism; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D011938:Rec A Recombinases / Q000235:genetics; D011995:Recombination, Genetic; D012097:Repressor Proteins / Q000378:metabolism
D004279:DNA, Viral; D012097:Repressor Proteins; D011938:Rec A Recombinases; C034510:CTCGAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific