A recombination function essential to the growth of bacteriophage P22

Botstein, David; Matz, M

doi:10.1016/0022-2836(70)90119-1

Cited by 129 publications

(76 citation statements)

References 25 publications

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“…Seven proteins of the 'phage structural module' were identified in the phage structural proteome (Figure 4, Supplementary Material S6): a phage head morphogenesis protein (ORF 20), a phage tail tape measure protein (ORF 43), a phage tail fibre adhesin (ORF 45) and four novel proteins (ORFs 26, 28, 35 and 46) that are now experimentally verified as structural proteins. The 'phage structural supermodule' of Phage H105/1, responsible for phage assembly and structure, is syntenous with the morphogenetic operon of other temperate phages and prophages (Figure 2a) (Botstein and Matz, 1970;Canchaya et al, 2003). Typical of a l-like morphogenetic operon (Casjens, 2003), ORF 20, encoding a putative head morphogenesis protein, is found in the 'DNA packaging and head formation' module with genes encoding the large and small terminases (ORFs 18 and 19), ATPbinding proteins that cut the concatenated phage DNA to prepare it for packaging (Black, 1989) (Figure 2a).…”

Section: Genome Features and Annotationsmentioning

confidence: 99%

Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1

et al. 2010

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Marine phages have an astounding global abundance and ecological impact. However, little knowledge is derived from phage genomes, as most of the open reading frames in their small genomes are unknown, novel proteins. To infer potential functional and ecological relevance of sequenced marine Pseudoalteromonas phage H105/1, two strategies were used. First, similarity searches were extended to include six viral and bacterial metagenomes paired with their respective environmental contextual data. This approach revealed 'ecogenomic' patterns of Pseudoalteromonas phage H105/1, such as its estuarine origin. Second, intrinsic genome signatures (phylogenetic, codon adaptation and tetranucleotide (tetra) frequencies) were evaluated on a resolved intragenomic level to shed light on the evolution of phage functional modules. On the basis of differential codon adaptation of Phage H105/1 proteins to the sequenced Pseudoalteromonas spp., regions of the phage genome with the most 'host'-adapted proteins also have the strongest bacterial tetra signature, whereas the least 'host'-adapted proteins have the strongest phage tetra signature. Such a pattern may reflect the evolutionary history of the respective phage proteins and functional modules. Finally, analysis of the structural proteome identified seven proteins that make up the mature virion, four of which were previously unknown. This integrated approach combines both novel and classical strategies and serves as a model to elucidate ecological inferences and evolutionary relationships from phage genomes that typically abound with unknown gene content.

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Section: Genome Features and Annotationsmentioning

confidence: 99%

Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1

et al. 2010

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“…la). Phages OX-174 (3,34,35) and M13 (36), lambda during its late life cycle (37,38), P2 (8), PM2 (39), T4 (40)(41)(42), P22 (43), the plasmid DNA of E. coli 15T- (44), and E. coli during mating (45,46) all appear to replicate in the rolling circle pattern (Fig. lb).…”

Section: Replication or Recombination?mentioning

confidence: 96%

Bacteriophage T7 DNA Replication: A Linear Replicating Intermediate

Wolfson

Dressler

Magazin

1972

Proc. Natl. Acad. Sci. U.S.A.

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The T7 chromosome in the first round of replication is a Y-shaped DNA rod. Thus, it differs from previously observed bacterial and viral replicating chromosomes that are circular.In microorganisms, viruses, and organelles, all actively replicating chromosomes observed are circular. Such circles have been of two types: Cairns circles (1) (Fig. la) and rolling circles (2) (Fig. lb). The replication of phage T7 DNA appears to be different: it does not involve a circular replicating intermediate. Instead, electron microscopy shows Y-shaped rods, analogous to those proposed 19 years ago by Watson and Crick (4) (Fig. lc).Experimental design When ("4N'H) phage particles infect cells growing in the presence of heavy isotopes ('5N2H), the density of the viral chromosomes increases from light (LL) toward hybrid (HL) as they begin to replicate. Molecules in their first round of replication contain predominantly light nucleotides (HLL), molecules at the end of the first round of replication are fully hybrid (HL), and molecules engaged in subsequent rounds of replication have densities ranging from hybrid (HL) to heavy (HH). Bacterial DNA remains fully heavy at all times. This protocol offers a rather sensitive way to fractionate candidates for partially replicated viral chromosomes and, most importantly for any electron microscopic study, allows one to obtain these chromosomes free of host-cell DNA.This extension of the Meselson and Stahl experiment (5) was developed by Ogawa, Tomizawa, and Fuke (6) to obtain partially replicated lambda chromosomes. The technique has been applied by Schn6s and Inman to study both lambda and P2 DNA replication(7, 8), and we have used it to study the replication of T7 DNA.Isolation of actively replicating T7 chromosomes Escherichia coli growing in a defined medium containing '5NH4Cl and 2H20 were infected at a multiplicity of ten with wild-type T7. The phage life cycle progressed normally, and ended 25 min later with a burst of 150 T7 particles per cell. At 10, 13, and 16 min after infection, aliquots of the culture were harvested as a source of actively replicating T7 DNA. The infected cells were opened with lysozyme and detergent, and the lysates were digested with Pronase. The intracellular DNA forms were purified by CsCl density gradient centrifugation. The material banding between light and hybrid (HLL) was recovered and examined in the electron microscope.The types of T7 molecules present in the HLL fractions from-a typical experiment are shown in Fig. 2. (a) 10% of the molecules were tangled and thus untraceable; these were of about T7 length, and were not long pieces of host-cell DNA.(b) 60% of the molecules were DNA rods of the same contour length as the mature T7 chromosome. Although most of these unit-length rods appeared in the HLL position of the CsCl gradient because of spillover from the LL and HL positions, some of them may have been the products of genetic recombination.(c) 20%o of the molecules were Y-shaped rods (Fig. 2a); in these, two arms of the Y were of eq...

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“…It is surprizing that the erf mutants were also unable to grow in ms mutants and were screened by this method. However, the erf mutants were easily identified from other conditional lethal mutants because of their inability to grow in recA cells [ 1,11 . Except for erf, 18 conditional mutants unable to grow in ms were isolated.…”

Section: Characteristics Of the Uv-sensitive Bacterialmentioning

confidence: 99%

“…On the other hand, the gene corresponding to ms should be present on wild type chromosome of P22, for the wild type phage can multiply in ms mutant. Here the erf corresponds to recA [1,11]. As a consequence, one of the x or y gene may perform similar function with ms gene.…”

Section: Characterization Of the Conditional Lethal Mutantsmentioning

confidence: 99%

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Bacterial Function Can Contribute to Replication of Salmonella Phage P22

Yamagami

Yamamoto

1973

Japanese Journal of Microbiology

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The UV sensitive bacterial mutants (abbreviated ms mutant) were isolated after N-methyl-N'-nitro-N-nitrosoguanidine (NG) mutagenesis.The ms mutants were found to be Hcr+ , Rec+ and sensitive to UV and NG. The significance of the ms mutants was inability to support the multiplication of several mutant phages of P22 which were also isolated by NG mutagenesis. These characters of ms mutants were caused by a single point mutation. Some of the mutant phages unable to grow in ms host were also unable to grow in recA hosts and determined to be erf mutants. The remaining phages were classified in two groups. One group of mutants formed minute plaques on wild type host and fell in the same complementation group (x mutation) and the other formed larger plaques than wild type plaques and belonged to an another complementation group (y mutation).These newly found two genes were essentially involved in the replication of viable P22 DNA. Of the three mutants, x and erf were moderately sensitive to UV irradiation in comparison with y and wild type. Study of lysis patterns showed that the y or erf infected ms culture lysed despite their inability of forming viable progenies, whereas, the x infected ms culture did not lysed . The new x and _y genes were both mapped in the early gene segment of P22 chromosome, on the left side of erf gene and between c3 and c2 genes, respectively. Based on these findings the contribution or substitution of the bacterial functions to the replication of bacteriophage was discussed.Bacteriophage P22 erf mutant cannot multiply in the recombination deficient, recA strains. Thus, it now seems clear that the bacterial function can contribute to the replication of bacteriophage [11] and that some bacterial functions substitute the phage functions for its replication. In order to demonstrate substitution of various phage functions by bacterial functions, it is necessary to provide condition in which phage mutants cannot multiply in bacterial mutants lacking the similar corresponding functions; this is accomplished by using phage mutants to grow in wild type host but not in nonpermissive hosts.It is reasonable to assume that common functions between phage and bacterial functions are involved in DNA replication, recombination and repair of DNA. Bacterial mutations related to the above functions are thought to be UV-sensitive. Therefore, UVsensitive bacterial mutants and phage mutants unable to grow in the bacterial mutants were sought. Experiments which show that the bacterial functions contribute or substitute the phage functions for its replication are presented and have been designed chiefly to illustrate the following points: (1) Isolation of UV-sensitive bacterial mutants; (2) isolation of phage mutants which are unable to grow in the above mutants (nonpermissive host) ; (3) identification and several characterization of the phage mutants; and (4) mapping of these newly found phage markers.

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A recombination function essential to the growth of bacteriophage P22

Cited by 129 publications

References 25 publications

Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1

Ecogenomics and genome landscapes of marine Pseudoalteromonas phage H105/1

Bacteriophage T7 DNA Replication: A Linear Replicating Intermediate

Bacterial Function Can Contribute to Replication of Salmonella Phage P22

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