Genome characteristics of a novel phage from Bacillus thuringiensis showing high similarity with phage from Bacillus cereus - PubMed (original) (raw)

Comparative Study

Genome characteristics of a novel phage from Bacillus thuringiensis showing high similarity with phage from Bacillus cereus

Yihui Yuan et al. PLoS One. 2012.

Abstract

Bacillus thuringiensis is an important entomopathogenic bacterium belongs to the Bacillus cereus group, which also includes B. anthracis and B. cereus. Several genomes of phages originating from this group had been sequenced, but no genome of Siphoviridae phage from B. thuringiensis has been reported. We recently sequenced and analyzed the genome of a novel phage, BtCS33, from a B. thuringiensis strain, subsp. kurstaki CS33, and compared the gneome of this phage to other phages of the B. cereus group. BtCS33 was the first Siphoviridae phage among the sequenced B. thuringiensis phages. It produced small, turbid plaques on bacterial plates and had a narrow host range. BtCS33 possessed a linear, double-stranded DNA genome of 41,992 bp with 57 putative open reading frames (ORFs). It had a typical genome structure consisting of three modules: the "late" region, the "lysogeny-lysis" region and the "early" region. BtCS33 exhibited high similarity with several phages, B. cereus phage Wβ and some variants of Wβ, in genome organization and the amino acid sequences of structural proteins. There were two ORFs, ORF22 and ORF35, in the genome of BtCS33 that were also found in the genomes of B. cereus phage Wβ and may be involved in regulating sporulation of the host cell. Based on these observations and analysis of phylogenetic trees, we deduced that B. thuringiensis phage BtCS33 and B. cereus phage Wβ may have a common distant ancestor.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1

Figure 1. Morphology of phage BtCS33 particles under TEM.

The virion was negatively stained with 2% potassium phosphotungstate. The white arrows indicate the putative tail fiber structure.

Figure 2

Figure 2. Genome organization of phage BtCS33.

The schematic represents the whole genome with the ORFs numbered from left to right. Different colors indicate three regions: the “late” region (red color), the “lysogeny-lysis control” region (green color) and the “early” region (blue color). Gray indicates the genes involved in host cell sporulation. Genes with unknown functions are indicated by white. The orientations of the arrows indicate the direction of transcription.

Figure 3

Figure 3. Dot plot alignment of genomes from B. thuringiensis phage BtCS33 and B. cereus phage Wbeta (Wβ).

Arrows indicate the start and the end positions of the most similar fragments on both genomes, corresponding to the dot plot. Both genomes were ranked in the orders of “late” region, the “lysogeney control” region and the “early” region.

Figure 4

Figure 4. Alignment of the proteomes of B. cereus phage Wbeta (Wβ) and B. thuringiensis phage BtCS33.

The putative proteins are numbered and different color arrows show the levels of amino acid identity: green indicates 20%–50%; blue, 50%–80%; and red, 80%–100%.

Figure 5

Figure 5. Phylogenetic tree constructed based on the complete geneome and the structural proteins.

(A) Phylogenetic tree constructed from the complete genome sequences of Bacillus spp. phages using a ClustalW alignment and the UPGMA (unweighted pair group method with arithmetic mean) with bootstrap analysis (1,000 replicates). (B) and (C) Phylogenetic trees constructed by using the neighbor-joining method and bootstrap analysis (1,000 replicates) of a Muscle alignment of amino acid sequences of the major capsid proteins and the tail fiber proteins, respectively. The host species is indicated after the name of each phage. ▴ represented the phage isolated in this study. The numbers on the lines indicated the supporting rates. The strains indicated the origin of the tail fiber proteins in (C). The numbers on the lines indicate the branch support.

Similar articles

Cited by

References

    1. Jensen GB, Hansen BM, Eilenberg J, Mahillon J. The hidden lifestyles of Bacillus cereus and relatives. Environ Microbiol. 2003;5(8):631–640. - PubMed
    1. Vilas-Boas GT, Peruca APS, Arantes OMN. Biology and taxonomy of Bacillus cereus, Bacillus anthracis, and Bacillus thuringiensis. Can J Microbiol. 2007;53(6):673–687. - PubMed
    1. Helgason E, Okstad OA, Caugant DA, Johansen HA, Fouet A, et al. Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis-One species on the basis of genetic evidence. Appl Environ Microbiol. 2000;66(6):2627–2630. - PMC - PubMed
    1. Daffonchio D, Cherif A, Borin S. Homoduplex and heteroduplex polymorphisms of the amplified ribosomal 16S–23S internal transcribed spacers describe genetic relationships in the “Bacillus cereus group”. Appl Environ Microbiol. 2000;66(12):5460–5468. - PMC - PubMed
    1. Agaisse H, Lereclus D. How does Bacillus-thuringiensis produce so much insecticidal crystal protein. J Bacteriol. 1995;177(21):6027–6032. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources