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Dibbens JA, Egan JB. Control of gene expression in the temperate coliphage 186. IX. B is the sole phage function needed to activate transcription of the phage late genes. Mol Microbiol 1992; 6:2629-42. [PMID: 1447972 DOI: 10.1111/j.1365-2958.1992.tb01440.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Using plasmid clones we have determined that the late control function B is the only phage function that is needed to activate a late promoter of coliphage 186, and we predict that it functions as an auxiliary factor to RNA polymerase in the activation of late transcription. We have also shown that a high concentration of B will activate late transcription from a prophage, and we conclude that replicating DNA is not a template requirement for B to function. The original demonstration of a need for the replication gene A in late transcription can be explained by the fact that replication leads to an increase in B gene dosage, with the consequent increase in B concentration leading to the efficient activation of the late promoters.
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Affiliation(s)
- J A Dibbens
- Department of Biochemistry, University of Adelaide, South Australia
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Dibbens JA, Gregory SL, Egan JB. Control of gene expression in the temperate coliphage 186. X. The cI repressor directly represses transcription of the late control gene B. Mol Microbiol 1992; 6:2643-50. [PMID: 1447973 DOI: 10.1111/j.1365-2958.1992.tb01441.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have found that the repressor of 186 lytic transcription, CI, represses transcription of the late control gene B, with no involvement of the B protein itself. In clone studies we showed that CI repressed transcription from the B promoter and that temperature inactivation of CIts led to B derepression. We conclude that CI repressor directly represses transcription of the B gene and, with prophage induction, it is probable that the inactivation of the CI repressor not only derepresses early lytic transcription, but also derepresses B gene transcription, leading to the activation of transcription from the late promoters.
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Affiliation(s)
- J A Dibbens
- Department of Biochemistry, University of Adelaide, South Australia
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Halling C, Sunshine MG, Lane KB, Six EW, Calendar R. A mutation of the transactivation gene of satellite bacteriophage P4 that suppresses the rpoA109 mutation of Escherichia coli. J Bacteriol 1990; 172:3541-8. [PMID: 2193910 PMCID: PMC213326 DOI: 10.1128/jb.172.7.3541-3548.1990] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Satellite bacteriophage P4 requires the products of the late genes of a helper such as P2 in order to grow lytically. The Escherichia coli rpoA109 mutation, which alters the alpha subunit of RNA polymerase, prevents transcription of the late genes of bacteriophage P2. Suppressor mutations that define the P2 ogr gene overcome this block. We found that P4 lytic growth using a P2 ogr+ prophage helper was prevented by the rpoA109 mutation but that this block was overcome when the P2 helper carried the suppressor mutation in the ogr gene. Furthermore, we isolated and characterized four independent mutations in P4, called org, that suppress the E. coli rpoA109 mutation by allowing P4 lytic growth using a P2 ogr+ helper. DNA sequence analysis revealed that the four independent org mutations are identical and that they occur in the P4 delta gene, which codes for a factor that positively regulates the transcription of the P2 and P4 late genes. delta is predicted to code for a basic 166-amino-acid residue protein. Each 83-residue half of the predicted delta gene product is similar to the predicted 72-residue proteins encoded by the ogr gene of P2 and the B gene of phage 186.
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Affiliation(s)
- C Halling
- Department of Molecular Biology, University of California, Berkeley 94720
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Richardson H, Puspurs A, Egan JB. Control of gene expression in the P2-related temperate coliphage 186. VI. Sequence analysis of the early lytic region. J Mol Biol 1989; 206:251-5. [PMID: 2704042 DOI: 10.1016/0022-2836(89)90539-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have completed the sequence of the 186 early lytic region and established that this region encodes the four genes CP75, CP76, CP77 and CP78, with CP79 the first gene of the next region. Functions have been assigned to the four early genes.
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Affiliation(s)
- H Richardson
- Scripps Clinic & Medical Foundation, La Jolla, CA 92037
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Richardson H, Egan JB. DNA replication studies with coliphage 186. II. Depression of host replication by a 186 gene. J Mol Biol 1989; 206:59-68. [PMID: 2704043 DOI: 10.1016/0022-2836(89)90523-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Using pre-labelling rather than pulse-labelling studies to determine rates of replication, we have shown that coliphage 186 infection is accompanied by a depression in host DNA replication. We have isolated mutants of the phage gene involved and mapped them in the early region of the phage genome. Sequencing the mutants ultimately led us to the identification of the gene that we have named the dhr gene.
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Affiliation(s)
- H Richardson
- Scripps Clinic and Medical Foundation, La Jolla, CA 92037
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Birkeland NK, Christie GE, Lindqvist BH. Directed mutagenesis of the bacteriophage P2 ogr gene defines an essential function. Gene 1988; 73:327-35. [PMID: 3072262 DOI: 10.1016/0378-1119(88)90497-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The ogr gene of bacteriophage P2 codes for a basic protein of 72 amino acids which is thought to be essential for activation of P2 late gene transcription. However, conditionally lethal mutations in the ogr gene have never been isolated. We have constructed a P2 ogr deletion mutant by in vitro techniques. This deletion phage, P2-del15, grows in a host which provides the ogr gene product in trans from a plasmid but fails to grow in hosts lacking the ogr plasmid. This demonstrates that the ogr gene is essential for P2 lytic growth. The deletion in P2del15 has removed about half of the carboxy-terminal part of the ogr gene. The transcript from this deletion mutant can be distinguished from the wild-type transcript by S1 nuclease protection. The analysis of such transcripts suggests that the ogr gene product may negatively regulate its own transcription.
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Affiliation(s)
- N K Birkeland
- Institute of Medical Biology, University of Tromsö, Norway
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Dale EC, Christie GE, Calendar R. Organization and expression of the satellite bacteriophage P4 late gene cluster. J Mol Biol 1986; 192:793-803. [PMID: 3295254 DOI: 10.1016/0022-2836(86)90029-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The satellite bacteriophage P4 genes for capsid size determination (sid), transactivation (delta), and polarity suppression (psu) are cotranscribed at late times after infection from a single P4 late promoter (Psid) that lies to the left of the sid gene. While the -10 region of this promoter is similar to the consensus sequence for Escherichia coli RNA polymerase, the -35 region shares no homology with known classes of E. coli promoters. The -10 and -35 regions of Psid share no homology with the late gene promoters of helper phage P2. Nonetheless, P4 late transcription is stimulated by coinfecting P2, as well as by P2 prophage. This stimulation depends on the P2 encoded transcription factor ogr; transcription from Psid is stimulated following the induction of the P2 ogr gene carried on a plasmid. P4 late transcription in the absence of P2 requires the P4 delta product, which is partially homologous to the P2 ogr gene product. DNA sequence analysis shows that the psu gene codes for a protein of Mr = 21,314 that is unrelated to the antitermination gene products of the lambdoid phages.
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Kalionis B, Pritchard M, Egan JB. Control of gene expression in the P2-related temperate coliphages. IV. Concerning the late control gene and control of its transcription. J Mol Biol 1986; 191:211-20. [PMID: 3806671 DOI: 10.1016/0022-2836(86)90258-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In this paper we have sequenced four amber mutants and thereby confirmed the gene D (CP65) and gene B (CP67) assignments made in the accompanying paper (Kalionis et al., 1986). We have also studied, by gel electrophoresis, the transcription patterns of gene B in vivo. In a lysogen, gene B is present on a short transcript under autogenous (negative) control. Upon prophage induction, this transcript is amplified, but later in the cycle gene B is present on a larger transcript that originates in the late region. We have detected two copies of an inverted repeat in the promoter region of the B gene that we predict is recognized by the B protein. One arm of this repeat is associated with three of four P2 late promoters, downstream from the start point of transcription. The repeat is not present in the promoter region of P2 ogr. We describe the considerable homology in amino acid sequence seen with the late control proteins 186 gpB, P4 gp delta and P2 gpOgr, and present a working model for control of late gene transcription.
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Kalionis B, Dodd IB, Egan JB. Control of gene expression in the P2-related template coliphages. III. DNA sequence of the major control region of phage 186. J Mol Biol 1986; 191:199-209. [PMID: 3806670 DOI: 10.1016/0022-2836(86)90257-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The PstI fragment (65.5% to 77.4%) of coliphage 186, known genetically to encode the major control genes, has been sequenced, and an analysis performed to assess coding capacity, transcription-translation signals, and to identify any other significant features. Our analysis indicates that the region encodes: seven genes, including the int and cI genes, which overlap, the late control gene B, and two genes, named CP75 and CP76, encoding potential DNA-binding proteins; a promoter pB and terminator tB for the rightward transcription of the B gene, and we predict the existence of this transcript in a lysogen; a promoter pL and terminator tL for leftward transcription that encodes the int and cI genes, and represents the presumed lysogenic transcript; a promoter pR for rightward transcription to give the presumed (early) lytic transcript that is overlapping and convergent with the lysogenic transcript; and finally, a potential operator site for repressor binding in the region of the pR promoter. Preliminary evidence is presented to support this analysis.
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Christie GE, Haggård-Ljungquist E, Feiwell R, Calendar R. Regulation of bacteriophage P2 late-gene expression: the ogr gene. Proc Natl Acad Sci U S A 1986; 83:3238-42. [PMID: 3458177 PMCID: PMC323488 DOI: 10.1073/pnas.83.10.3238] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The ogr gene product of bacteriophage P2 is a positive regulatory factor required for P2 late-gene transcription. We have determined the nucleotide sequence of the ogr gene, which encodes a basic polypeptide of 72 amino acids. P2 growth is blocked by a host mutation, rpoA109, in the alpha subunit of DNA-dependent RNA polymerase. The ogr52 mutation, which allows P2 to grow in an rpoA109 strain, was shown to be a single nucleotide change, in the codon for residue 42, that changes tyrosine to cysteine. The predicted amino acid sequence of the Ogr protein does not show similarity to DNA-binding proteins that are known to affect promoter recognition, to sigma factors, or to other characterized transcriptional regulatory proteins. We have inserted the ogr gene into a plasmid under control of the leftward promoter and operator of bacteriophage lambda. Thermal induction of ogr gene expression in this plasmid results in overproduction of a small protein that has been shown by complementation to possess Ogr function.
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Hocking SM, Egan JB. Genetic studies of coliphage 186. II. Genes associated with phage replication and host cell lysis. J Virol 1982; 44:1068-71. [PMID: 6757461 PMCID: PMC256367 DOI: 10.1128/jvi.44.3.1068-1071.1982] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
DNA synthesis in coliphage 186-infected cells was investigated. Phage 186 appeared to inhibit host DNA synthesis early in infection. The subsequent synthesis of phage 186 DNA was dependent on the product of 186 gene A. The product of gene B controlled both the production of late 186 proteins and the cessation of 186 DNA synthesis, and the products of genes O and P had no influence on 186 DNA synthesis. The product of gene P controlled host cell lysis, and the product of gene O may have some regulatory function.
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Sauer B, Calendar R, Ljungquist E, Six E, Sunshine MG. Interaction of satellite phage P4 with phage 186 helper. Virology 1982; 116:523-34. [PMID: 6278725 DOI: 10.1016/0042-6822(82)90145-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Hooper I, Woods WH, Egan B. Coliphage 186 Replication is delayed when the host cell is UV irradiated before infection. J Virol 1981; 40:341-9. [PMID: 6459463 PMCID: PMC256634 DOI: 10.1128/jvi.40.2.341-349.1981] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In contrast to results with injections by lambda and P2, the latent period for infection by coliphage 186 is extended when the host cell is UV irradiated before infection. We find that 186 replication is significantly delayed in such a cell, even though the phage itself has not been irradiated. In contrast, replication of the closely related phage P2 under the same conditions is not affected.
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Kalionis B, Egan JB. Orientation of separated DNA strands of coliphage 186 relative to its genetic map. Gene X 1981; 15:95-8. [PMID: 7028570 DOI: 10.1016/0378-1119(81)90107-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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