Bacteriophage SPO1

Stewart, Christopher

doi:10.1007/978-1-4684-5424-6_11

Cited by 15 publications

(8 citation statements)

References 122 publications

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“…6). We examined transcription from a middle promoter (PMII3) and observed that the tfl-ts mutation affected the abundance of RNA initiating at that promoter and presumably, therefore, the capacity to synthesize the replication protein gp27 (43) late in infection in a similar way. This is evidence that TF1 functions at the level of transcription, or at least transcript accumulation, in shutting off middle gene expression.…”

Section: Discussionmentioning

confidence: 99%

Construction and properties of a temperature-sensitive mutation in the gene for the bacteriophage SPO1 DNA-binding protein TF1

Sayre

Geiduschek

1990

J Bacteriol

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(transcription factor) 1 derives from that property. TF1 binds to certain specific sites in SPOl DNA with a selectively high affinity (19,20). In that selectivity, it resembles one other member of the type II DNA-binding protein family, the Escherichia coli integration host factor (8, 46).Although we have been able to show that the function of TF1 is required for SPO1 development, we have failed to construct suppressor-sensitive TF1 mutants (41). Speculatively rationalizing this failure in terms of a stringent requirement for an abundant supply of TF1 during infection, we have turned instead to a search for temperature-sensitive (ts) mutants, basing our searching strategy on structural considerations and site-directed mutagenesis. In this paper, we report on the construction and properties of a ts mutant in the gene coding for TF1. A segment of the SPO1 DNA insert in pXbal-29 that covers the C-proximal segment of gene 30 and the upstream segment of the TF1 transcription unit (see Fig. 3D), and the SPOl segment in pLeu44 covering the TF1 gene (see Fig. 3C) were joined at their common HgiAI ends and inserted between the SmaI and EcoRI sites of M13mpl9 replicativeform DNA. The resulting 950-base-pair insert contained a contiguous segment of wild-type gene 30 and the entire leu44 TF1 allele (41), as diagrammed below (see Fig. 3B). The encapsidated DNA of this construction contains the nontranscribed strand of the TF1 gene (18) and is designated m30bcLeu44. Oligonucleotide-directed mutagenesis of the 4672 on May 11, 2018 by guest MATERIALS AND METHODS

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Section: Discussionmentioning

confidence: 99%

Construction and properties of a temperature-sensitive mutation in the gene for the bacteriophage SPO1 DNA-binding protein TF1

Sayre

Geiduschek

1990

J Bacteriol

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“…B. cereus is genotypically closely related to B. thuringiensis, and it has been suggested that they be grouped into a single species (4). In contrast to the well-studied phages infecting B. subtilis (29,40), no information is available on the molecular biology and relationships of viruses for the B. cereus-B. thuringiensis group.…”

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Three Bacillus cereus bacteriophage endolysins are unrelated but reveal high homology to cell wall hydrolases from different bacilli

et al. 1997

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The ply genes encoding the endolysin proteins from Bacillus cereus phages Bastille, TP21, and 12826 were identified, cloned, and sequenced. The endolysins could be overproduced in Escherichia coli (up to 20% of total cellular protein), and the recombinant proteins were purified by a two-step chromatographical procedure. All three enzymes induced rapid and specific lysis of viable cells of several Bacillus species, with highest activity on B. cereus and B. thuringiensis. Ply12 and Ply21 were experimentally shown to be N-acetylmuramoyl-L-alanine amidases (EC 3.5.1.28). No apparent holin genes were found adjacent to the ply genes. However, Ply21 may be endowed with a signal peptide which could play a role in timing of cell lysis by the cytoplasmic phage endolysin. The individual lytic enzymes (PlyBa, 41.1 kDa; Ply21, 29.5 kDa, Ply12, 27.7 kDa) show remarkable heterogeneity, i.e., their amino acid sequences reveal only little homology. The N-terminal part of Ply21 was found to be almost identical to the catalytic domains of a Bacillus sp. cell wall hydrolase (CwlSP) and an autolysin of B. subtilis (CwlA). The C terminus of PlyBa contains a 77-amino-acid sequence repeat which is also homologous to the binding domain of CwlSP. Ply12 shows homology to the major autolysins from B. subtilis and E. coli. Comparison with database sequences indicated a modular organization of the phage lysis proteins where the enzymatic activity is located in the N-terminal region and the C-termini are responsible for specific recognition and binding of Bacillus peptidoglycan. We speculate that the close relationship of the phage enzymes and cell wall autolysins is based upon horizontal gene transfer among different Bacillus phages and their hosts.Numerous bacteriophages for the genus Bacillus have been isolated, and at present, they are grouped into 33 phage species. With one exception, all of them belong to the tailed phages (1). Lytic activity is not necessarily restricted to a single species, especially with respect to the phages used for typing strains of Bacillus cereus and Bacillus thuringiensis (2, 35). B. cereus is genotypically closely related to B. thuringiensis, and it has been suggested that they be grouped into a single species (4). In contrast to the well-studied phages infecting B. subtilis (29,40), no information is available on the molecular biology and relationships of viruses for the B. cereus-B. thuringiensis group.At the end of their multiplication cycle, most bacteriophages are released from the cells through the action of endogenous cell wall hydrolases, termed endolysins or phage lysins (for a review, see reference 38). Several genes encoding lysins from phages infecting both gram-negative and gram-positive hosts have been cloned and sequenced. In some cases, the catalytic mechanisms have been determined, which place the phage lysins into three distinct groups: amidases, muramidases (glycosidases and transglycosylases), and endopeptidases (38). Recently, a fourth type of enzyme was described (L-alanoyl-Dglutamate pe...

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“…More likely, however, is the modification of host RNA polymerase by phage-encoded sigma-like factors, which regulate sequential gene expression by altering the recognition properties of the core enzyme. This topic is well studied for the virulent Bacillus subtilis phage SPO1 (39), which is morphologically similar to A511.…”

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Organization and transcriptional analysis of the Listeria phage A511 late gene region comprising the major capsid and tail sheath protein genes cps and tsh

Loessner

Scherer

1995

J Bacteriol

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A511 is a broad-host-range, virulent myovirus for Listeria monocytogenes. The genes encoding major structural proteins of the capsid (cps) and tail sheath (tsh) were mapped to a 10.15-kb late gene fragment. We have determined the complete nucleotide sequence of this region and confirmed the identities of Cps (48.7 kDa) and Tsh (61.3 kDa) by N-terminal amino acid sequencing of both proteins. In addition, nine other open reading frames were identified. On the basis of amino acid sequence homologies to known phage-encoded proteins, some putative functions and locations could be assigned to some of the deduced gene products. We present evidence that the cps product is proteolytically cleaved between Lys-23 and Ser-24 to yield the 444-residue polypeptide found in the mature viral capsid. We also found that the N-terminal methionine is absent from the mature tail sheath protein. cps and tsh are late genes; mRNAs first appear 15 to 20 min after infection of L. monocytogenes. Northern (RNA) hybridizations of total late mRNA with specific oligonucleotide probes were used to determine the sizes of respective transcripts. Primer extension analyses enabled the positive identification of six late promoters, which were found to differ from those identified in the chromosome of Listeria spp. The bulk of transcripts from cps and tsh arise from two phage promoters with identical 13-nucleotide sequences (TGCTAGATTATAG [core region underlined]) in the ؊10 region which we speculate determines specific and timed expression of these genes. A 123-nucleotide leader sequence at the 5 end of the cps transcript was predicted to form a strong secondary structure (⌬G ‫؍‬ ؊40.7 kcal [؊170.3 kJ]/mol). Our results show that the strongly expressed A511 cps and tsh genes are included in two separate gene clusters and are independently regulated at the transcriptional level.Listeria monocytogenes is an opportunistic gram-positive pathogen responsible for a variety of severe infections in both animals and humans (reviewed in reference 17). Much research is presently directed towards understanding the molecular mechanisms of its pathogenicity, as well as developing tools for molecular research and rapid detection methods.Listeria bacteriophage A511 is the only known virulent phage for this genus and is unrelated to all other Listeria phages (31, 43). A511 has an extremely broad host range, being capable of lysing approximately 95% of all L. monocytogenes strains of serovars 1/2 and 4b (30,33). This makes it useful in bacteriophage typing of listeriae (29, 30) and renders it a promising candidate for development of a specific reporter vehicle for rapid detection of Listeria spp. in foods and environmental samples.The A511 virion is a myovirus with an isometric capsid 88 nm in diameter and a straight tail 200 nm long with a contractile sheath around the inner tail tube (43). Upon recognition of its cell surface receptor (42), the sheath is contracted to twothirds of its original length and the linear double-stranded DNA molecule of approximately 116 ...

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Bacteriophage SPO1

Cited by 15 publications

References 122 publications

Construction and properties of a temperature-sensitive mutation in the gene for the bacteriophage SPO1 DNA-binding protein TF1

Construction and properties of a temperature-sensitive mutation in the gene for the bacteriophage SPO1 DNA-binding protein TF1

Three Bacillus cereus bacteriophage endolysins are unrelated but reveal high homology to cell wall hydrolases from different bacilli

Organization and transcriptional analysis of the Listeria phage A511 late gene region comprising the major capsid and tail sheath protein genes cps and tsh

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