Physical map of coliphage BF23 DNA

Heller, Knut J.; Krauel, Verena

doi:10.1016/0378-1119(86)90088-0

Cited by 2 publications

(3 citation statements)

References 6 publications

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“…BF23+ DNA has been mapped for seven restriction enzymes (20,34). We mapped the cleavage sites for EcoRV, KpnI, SmaI, and SstI for the entire BF23 DNA (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…For AvaI this was done in a manner similar to the mapping of sites within the T5 SalC fragment. In particular, we compared the BF23 BamHI fragments Bam4 (contains rTR) and BamS (contains lTR) and in addition, the Hindlll fragment Hin4 (contains rTR) (20). The PvuII site was mapped by comparing a PvuII digest with a PvuII-SmaI double digest; a 10.3-kbp fragment from the single digest disappeared, and instead a 9.0-and a 1.3-kbp fragment appeared in the double digest.…”

Section: Resultsmentioning

confidence: 99%

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Cloning, sequencing, and recombinational analysis with bacteriophage BF23 of the bacteriophage T5 oad gene encoding the receptor-binding protein

Krauel

Heller

1991

J Bacteriol

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Binding of bacteriophage T5 to its receptor, the Escherichia coli FhuA protein, is mediated by tail protein pb5. In this article we confirm that pb5 is encoded by the T5 oad gene and describe the isolation, expression, and sequencing of this gene. In order to locate oad precisely, we analyzed recombinants between BF23, a T5-related phage with a different host range, and plasmid clones containing segments of the T5 chromosome. This analysis also showed that oad has little or no homology with hrs, the analogous BF23 gene. We were able to overproduce a protein that comigrates with pb5 after fusing a 2-kb segment containing oad to a phage T7

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“…BF23+ DNA has been mapped for seven restriction enzymes (20,34). We mapped the cleavage sites for EcoRV, KpnI, SmaI, and SstI for the entire BF23 DNA (Fig.…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Cloning, sequencing, and recombinational analysis with bacteriophage BF23 of the bacteriophage T5 oad gene encoding the receptor-binding protein

Krauel

Heller

1991

J Bacteriol

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“…The cloned fragments were located from coordinates 79.1 to 103.6 kb, corresponding to about 21% of the total phage genome. In addition, the cloning and construction of a restriction map of the 4.3-kb HindIII fragment of pHI3 permitted us to assign the positions of two small contiguous PstI fragments which were not determined previously (12), that is, 0.2-kb PstI-12 and 0.8-kb PstI-11 fragments from left to right in the physical map (Fig. la).…”

Section: Resultsmentioning

confidence: 99%

Cloning, sequencing, and expression of bacteriophage BF23 late genes 24 and 25 encoding tail proteins

et al. 1994

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Two bacteriophage BF23 late genes, genes 24 and 25, were isolated on a 7.4-kb PstI fragment from the phage DNA, and their nucleotide sequences were determined. Gene After infection of Escherichia coli cells, bacteriophage BF23, a close relative of T5, expresses in a temporal sequence at least three classes of phage-specific genes, designated pre-early, early, and late genes (for a review, see reference 20). Expression of pre-early genes, measured by protein synthesis, starts immediately after infection and continues for about 10 min, at which time the rate of expression decreases rapidly. Early genes which are further classified into two groups, Ea and Eb, are mainly expressed between 7 and 20 min after infection, while late genes are expressed from 15 min until lysis of the host cells (25).The temporal expression of BF23 genes was shown to be regulated at the transcriptional level in a tightly coordinated manner between one step and its subsequent steps throughout the propagation of the phage (14). This process includes a unique two-step DNA transfer mechanism. About 8% of the phage DNA corresponding to the pre-early gene region is initially transferred into the host cell, and 92% of the DNA containing early and late genes enters the host cell as the second step of the DNA transfer, which depends on the actions of at least two pre-early genes, genes 1 and 2. The onset of late gene expression is coupled to the shutoff of Eb early gene expression. This step is controlled by the actions of at least three regulatory early genes, genes 10, 14, and 19. Additionally, gene 10 has been shown to be involved in the shutoff of Ea early gene expression as well.Transcription of BF23 genes is catalyzed by the host RNA polymerase. Several lines of evidence indicated that the enzyme was successively modified by interaction with gp2, gplO, gp14, and gp19, which are the products of genes 2, 10, 14, and 19, respectively (14). gp2 binds to the enzyme to form an enzyme-gp2 complex in the earlier stage of infection but is replaced by gplO and gpl4 in the later stage. This exchange * Corresponding author. Phone: (+81) 424-83-2161. Fax: (+81) 424-84-4518. reaction requires gpl9 and, hence, associates with the switch of gene expression from Eb early to late. However, the precise functions of these regulatory proteins are unknown.In this report, we describe cloning and sequencing of two late genes, genes 24 and 25, which encode minor and major tail proteins, respectively. We identify and characterize a possible promoter for these genes in the cloned gene system as well as in the normal infection system. Evidence indicating that genes 24 and 25 constitute a single operon is presented. On the basis of these results, we discuss the roles of the regulatory genes in the temporal expression of BF23 genes. MATERUILS AND METHODSBacteria, phage, and plasmids. Bacterial strains and plasmids used in this study are listed in

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Physical map of coliphage BF23 DNA

Cited by 2 publications

References 6 publications

Cloning, sequencing, and recombinational analysis with bacteriophage BF23 of the bacteriophage T5 oad gene encoding the receptor-binding protein

Cloning, sequencing, and recombinational analysis with bacteriophage BF23 of the bacteriophage T5 oad gene encoding the receptor-binding protein

Cloning, sequencing, and expression of bacteriophage BF23 late genes 24 and 25 encoding tail proteins

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