Multiple repressor binding sites in the genome of bacteriophage P1.

Velleman, M; Dreiseikelmann, Brigitte; Schuster, Hans‐Uwe

doi:10.1073/pnas.84.16.5570

Cited by 31 publications

(14 citation statements)

References 36 publications

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“…The ban gene (67,237), which can complement the replicative helicase defect of E. coli dnaB mutants, was mapped to a 1.6-kb region located 2.5 kb downstream of the bivalent C1 operator Obanab (formerly Op72ab; Table 6) (132,316). It encodes a 455-residue protein (195) identical in 78% of its amino acid sequence to E. coli DnaB.…”

Section: Methodsmentioning

confidence: 99%

Genome of Bacteriophage P1

et al. 2004

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P1 is a bacteriophage of Escherichia coli and other enteric bacteria. It lysogenizes its hosts as a circular, low-copy-number plasmid. We have determined the complete nucleotide sequences of two strains of a P1 thermoinducible mutant, P1 c1-100. The P1 genome (93,601 bp) contains at least 117 genes, of which almost two-thirds had not been sequenced previously and 49 have no homologs in other organisms. Protein-coding genes occupy 92% of the genome and are organized in 45 operons, of which four are decisive for the choice between lysis and lysogeny. Four others ensure plasmid maintenance. The majority of the remaining 37 operons are involved in lytic development. Seventeen operons are transcribed from 70 promoters directly controlled by the master phage repressor C1. Late operons are transcribed from promoters recognized by the E. coli RNA polymerase holoenzyme in the presence of the Lpa protein, the product of a C1-controlled P1 gene. Three species of P1-encoded tRNAs provide differential controls of translation, and a P1-encoded DNA methyltransferase with putative bifunctionality influences transcription, replication, and DNA packaging. The genome is particularly rich in Chi recombinogenic sites. The base content and distribution in P1 DNA indicate that replication of P1 from its plasmid origin had more impact on the base compositional asymmetries of the P1 genome than replication from the lytic origin of replication.

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Section: Methodsmentioning

confidence: 99%

Genome of Bacteriophage P1

et al. 2004

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“…Stable lysogeny is maintained by the action of the components of the tripartite immunity system (for a review, see reference 10). The C1 repressor protein acts as a central regulator by binding to and negatively regulating promoter elements for a variety of genes (7,8,11,12,16,17,28). The C1 asymmetric operator sites (consensus sequence ATTGCTCTAATAAATTT) are widely dispersed over the P1 genome and are numbered according to their positions on the P1 genetic map (10,30).…”

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Controlled Expression in Klebsiella pneumoniae and Shigella flexneri Using a Bacteriophage P1-Derived C1-Regulated Promoter System

et al. 2001

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The utility of promoters regulated by the bacteriophage P1 temperature-sensitive C1 repressor was examined in Shigella flexneri and Klebsiella pneumoniae. Promoters carrying C1 operator sites driving LacZ expression had induction/repression ratios of up to 240-fold in S. flexneri and up to 50-fold in K. pneumoniae. The promoters exhibited remarkably low basal expression, demonstrated modulation by temperature, and showed rapid induction. This system will provide a new opportunity for controlled gene expression in enteric gram-negative bacteria.Many regulated promoter systems have been described for use in Escherichia coli. These systems include promoters regulated by LacI (2), AraC (9), and TetR (18) or combinations that can provide both low basal and high induced expression. Each system has shown utility with varying success in other bacteria, such as Pseudomonas aeruginosa (6), Corynebacterium glutamicum (4), Agrobacterium tumefaciens (22), and Xanthomonas campestris (27). However, few or no data exist for a regulated promoter system in the medically important species Klebsiella pneumoniae (14) and Shigella flexneri. Klebsiella species cause approximately 8% of nosocomial infections in the United States and are commonly found in both humans and the environment (23). In contrast, Shigella species, found mainly in humans, cause shigellosis, which is characterized by cramps, fever, and dysentery (1).The temperate bacteriophage P1 can infect and lysogenize several enterobacterial species, including K. pneumoniae and Shigella dysenteriae (21,30). Stable lysogeny is maintained by the action of the components of the tripartite immunity system (for a review, see reference 10). The C1 repressor protein acts as a central regulator by binding to and negatively regulating promoter elements for a variety of genes (7,8,11,12,16,17,28). The C1 asymmetric operator sites (consensus sequence ATTGCTCTAATAAATTT) are widely dispersed over the P1 genome and are numbered according to their positions on the P1 genetic map (10,30).In this report, we describe a temperature-sensitive C1-regulated promoter system in a broad-host-range plasmid for controlled gene expression in both K. pneumoniae and S. flexneri.Characteristics and construction of the expression vectors. The lacZ reporter gene vectors were constructed in the broadhost-range gram-negative plasmid pBBR122 (Mobitec). The lacZ gene was placed under the transcriptional control of two C1-regulated promoters (Fig. 1A). The Pro1 promoter is based on the promoter responsible for driving ban gene expression in bacteriophage P1 and has been shown to be effectively repressed in E. coli in the presence of C1 (11, 26). It consists of two overlapping C1 operator sites but lacks consensus E. coli Ϫ10 and Ϫ35 promoter elements. In contrast, the artificial promoter (Pro2) contains a consensus C1 operator site flanked by consensus Ϫ10 and Ϫ35 promoter elements. To prevent read-through from cryptic promoters and runaway transcription, the ribosomal terminators rrnB T1 T2 (5) and TL 17 (29) we...

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“…For example, P1 genes for both immunity control and morphogenesis are widely dispersed over the genome (50,62,63). The presence of at least 14 operator sites for the P1 cI repressor protein (8,15,16,28,29,59) and the tripartite immunity system of the phage (64) indicate the degree of complexity which P1 faces in regulating and expressing its genetic information.While the lysogenic condition of P1 has been studied intensively (for a recent review, see reference 64), relatively little is known about the regulation of the lytic growth cycle. A few functions which are under transcriptional control of the P1 cI repressor have been identified (8,10).…”

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Bacteriophage P1 gene 10 encodes a trans-activating factor required for late gene expression

1991

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Amber mutants of bacteriophage P1 were used to identify functions involved in late regulation of the P1 lytic growth cycle. A single function has been genetically identified to be involved in activation of the phage-specific late promoter sequence P. In vivo, P1 gene 10 amber mutants fail to trans activate a lacZ operon fusion under the transcriptional control of promoter Ps. Several P1 segments, mapping around position 95 on the P1 chromosome, were cloned into multicopy plasmid vectors. Some of the cloned DNA segments had a deleterious effect on host cells unless they were propagated in a P1 lysogenic background. By deletion and sequence analysis, the harmful effect could be delimited to a 869-bp P1 fragment, containing a 453-bp open reading frame. This open reading frame was shown to be gene 10 by sequencing the amber mutation amlO.1 and by marker rescue experiments with a number of other gene 10 amber mutants. Gene 10 codes for an 18.1-kDa protein showing an unusually high density of charged amino acid residues. No significant homology to sequences present in the EMBL/GenBank data base was found, and the protein contained none of the currently known DNA-binding motifs. An in vivo trans activation assay system, consisting of gene 10 under the transcriptional control of an inducible promoter and a gene SllacZ fusion transcribed from Ps, was used to show that gene 10 is the only phage-encoded function required for late promoter activation.The temperate bacteriophage P1 propagates on several enterobacterial species, including Escherichia coli (64). The linear DNA molecule carried in a phage particle is about 100 kb in size and has a terminal redundancy of 8 to 12% (32, 65). As a prophage, P1 is a low-copy-number plasmid of about 90 kb (3, 33).The genome of P1 is organized in relatively short transcriptional units and in this respect resembles the virulent bacteriophage T4 (43) rather than the temperate lambdoid phages (57). For example, P1 genes for both immunity control and morphogenesis are widely dispersed over the genome (50,62,63). The presence of at least 14 operator sites for the P1 cI repressor protein (8,15,16,28,29,59) and the tripartite immunity system of the phage (64) indicate the degree of complexity which P1 faces in regulating and expressing its genetic information.While the lysogenic condition of P1 has been studied intensively (for a recent review, see reference 64), relatively little is known about the regulation of the lytic growth cycle. A few functions which are under transcriptional control of the P1 cI repressor have been identified (8,10). Among those is the repL function, which is essential for the lytic replication of the phage genome (9,25,52).Recently, a new class of P1 promoters, controlling the late genes encoded by the tail fiber and the dar operons, has been identified (21,22

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Multiple repressor binding sites in the genome of bacteriophage P1.

Cited by 31 publications

References 36 publications

Genome of Bacteriophage P1

Genome of Bacteriophage P1

Controlled Expression in Klebsiella pneumoniae and Shigella flexneri Using a Bacteriophage P1-Derived C1-Regulated Promoter System

Bacteriophage P1 gene 10 encodes a trans-activating factor required for late gene expression

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