The infection of Escherichia coli cells by bacteriophage lambda results in bifurcated means of propagation, where the phage decides between the lytic and lysogenic pathways. Although traditionally thought to be mutually exclusive, increasing evidence suggests that this lysis-lysogeny decision is more complex than once believed, but exploring its intricacies requires an improved resolution of st...

Human placental DNA, enriched for ribosomal sequences, was cloned in the phage vector lambda Charon 16A. Recombinants containing 28S rDNA sequences were isolated, and all were found to have deletions in the insert and/or vector DNA. Electron microscopic analysis was used to map the deletions and provide evidence that unstable forms of the recombinants can revert to the original vector or underg...

Bacteriophage lambda DNA can be packaged in vitro into preformed proheads to generate plaque-forming units. This complex set of reactions is initiated when lambda DNA is mixed with the product of the phage A gene, and proheads. Because proheads are an essential early reactant, the system has potential as an assay for the formation of biologically active proheads. When extracts of cells infected...

Thermoinduction of cells of E. coli carrying prophage lambdacI857 within the bfe gene brings about not only "escape synthesis" of core subunits of the DNA-dependent RNA polymerase (RNA nucleotidyltransferase, nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2-7-7-6), but also a striking stimulation of sigma factor synthesis. The latter phenomenon, termed sigma induction, is generally obser...

The replication of herpes simplex virus type 1 (HSV-1) DNA is associated with a high degree of homologous recombination. While cellular enzymes may take part in mediating this recombination, we present evidence for an HSV-1-encoded recombinase activity. HSV-1 alkaline nuclease, encoded by the UL12 gene, is a 5'-->3' exonuclease that shares homology with Redalpha, commonly known as lambda exonuc...

Although most of the 73 open reading frames (ORFs) in bacteriophage λ have been investigated intensively, the function of many genes in host-phage interactions remains poorly understood. Using yeast two-hybrid screens of all lambda ORFs for interactions with its host Escherichia coli, we determined a raw data set of 631 host-phage interactions resulting in a set of 62 high-confidence interactio...

A phage directing the synthesis of an abundant 45-kD Treponema pallidum surface protein was isolated from an EMBL-4 bacteriophage lambda library of T. pallidum DNA. The recombinant phage was identified using an mAb that was directed toward an immunodominant, outer envelope T. pallidum protein designated P6. The recombinant P6 protein possessed the same mol mass as the native treponemal antigen ...

Knowledge of the three-dimensional structures of the lambda-Cro and lambda-repressor proteins in complex with DNA has made it possible to evaluate how these proteins discriminate between different operators in phage lambda. As anticipated in previous studies, the helix-turn-helix units of the respective proteins bind in very different alignments. In Cro the recognition helices are 29 A apart an...

A novel phage lambda mutation, called dc10, which interferes with proper lambda head assembly has been isolated and characterized. Phage lambda carrying this mutation is (i) unable to form plaques at 30 or 37 degrees C but does so at 42 degrees C and (ii) unable to form plaques at 42 degrees C on pN-constitutive hosts. Both properties are due to dc10 since all phage revertants for one phenotype...

The lytic-lysogenic switch of the temperate lactococcal phage TP901-1 is fundamentally different from that of phage lambda. In phage TP901-1, the lytic promoter PL is repressed by CI whereas repression of the lysogenic promoter PR requires the presence of both of the antagonistic regulator proteins, MOR and CI. We model the central part of the switch and compare the two cases for PR repression:...