Lambda phage

About: Lambda phage is a research topic. Over the lifetime, 1609 publications have been published within this topic receiving 84675 citations. The topic is also known as: Enterobacteria phage lambda.

Identification of polypeptides encoded by an Escherichia coli locus (hflA) that governs the lysis-lysogeny decision of bacteriophage lambda.

Abstract: We report the cloning of the Escherichia coli hflA locus, which governs stability of phage lambda cII protein and which has been proposed to encode or regulate a cII-specific protease. The hflA locus was cloned on an 18-kilobase DNA fragment by selecting for plasmids that carry the neighboring purA gene. The boundaries of hflA were delimited by analysis of deletions and insertions constructed in vitro and by use of transposon Tn1000. Maxicell analysis of the proteins encoded by the hflA-containing fragment shows that hflA consists of at least two nonoverlapping genes, hflC and hflK, encoding polypeptides of 37,000 (C) and 46,000 (K) daltons. We observe that insertions into one gene eliminate the corresponding polypeptide and greatly reduce synthesis of the other. We suggest that these two polypeptides (K and C) interact to form a multimeric complex and that free subunits are unstable. We have constructed two types of fusions between hflA and lacZ. One is an hflC-lacZ protein fusion constructed in vitro; the other is an hfl-lacZ operon fusion in which a Mu dX(Apr lac) has inserted into the hflK gene. We have used the operon fusion to infer the direction of transcription of the hflK gene--toward hflC and in the same direction as hflC. Last, we describe evidence that hflA contains an additional gene, hflX, encoding a 50,000-dalton polypeptide.

Chi activity during transduction-associated recombination.

Abstract: Chi is a genetic element that stimulates phage lambda recombination by the Escherichia coli recBC pathway during lytic infection [Stahl, F. W. (1979) Annu. Rev. Genet. 13, 7--24]. Herein we show that chi in lambda prophage influences exchange distribution in P1 phage-mediated transduction and in conjugation. This demonstration encourages the view that chi may influence genetic exchange in E. coli in the total absence of lambda.

Overproduction and purification of the connector protein of Bacillus subtilis phage ø29

Abstract: A phi 29 DNA fragment containing genes 10 and 11, coding for the connector protein and the lower collar protein, respectively, has been cloned in the pBR322 derivative plasmid pKC30 under the control of the PL promoter of phage lambda Two polypeptides with the electrophoretic mobility of proteins p10 and p11 were labelled with 35S-methionine after heat induction The proteins were characterized as p10 and p11 by radioimmunoassay and they represented about 10% and 7%, respectively, of the total E coli protein after 4 hours of induction These proteins represent less than 1% of the B subtilis protein in phi 29-infected cells Protein p10 has been highly purified from the E coli cells carrying the recombinant plasmid Antibodies raised against the purified protein p10 reacted with the connector protein produced in phi 29-infected B subtilis