Mycobacteriophage L5 infection of <i>Mycobacterium bovis</i> BCG: implications for phage genetics in the slow‐growing mycobacteria

Fullner, Karla Jean; Hatfull, Graham F.

doi:10.1046/j.1365-2958.1997.6111984.x

Cited by 43 publications

(32 citation statements)

References 32 publications

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“…One may, therefore, speculate that because these two phages have a very wide range of hosts, infecting both fast-growing and slow-growing Mycobacteria (Fullner and Hatfull 1997;Ford et al 1998), palindrome avoidance is motivated by the existence of RMS in some other host. Indeed, the existence of RMS has been reported in five different species of closely related Mycobacteria (Roberts and Macelis 2000).…”

Section: Roles Of Restriction Systems In Bacteriamentioning

confidence: 99%

Evolutionary Role of Restriction/Modification Systems as Revealed by Comparative Genome Analysis

Rocha¹

2001

Genome Research

107

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Type II restriction modification systems (RMSs) have been regarded either as defense tools or as molecular parasites of bacteria. We extensively analyzed their evolutionary role from the study of their impact in the complete genomes of 26 bacteria and 35 phages in terms of palindrome avoidance. This analysis reveals that palindrome avoidance is not universally spread among bacterial species and that it does not correlate with taxonomic proximity. Palindrome avoidance is also not universal among bacteriophage, even when their hosts code for RMSs, and depends strongly on the genetic material of the phage. Interestingly, palindrome avoidance is intimately correlated with the infective behavior of the phage. We observe that the degree of palindrome and restriction site avoidance is significantly and consistently less important in phages than in their bacterial hosts. This result brings to the fore a larger selective load for palindrome and restriction site avoidance on the bacterial hosts than on their infecting phages. It is then consistent with a view where type II RMSs are considered as parasites possibly at the verge of mutualism. As a consequence, RMSs constitute a nontrivial third player in the host-parasite relationship between bacteria and phages.Classic type II restriction modification systems (RMSs) comprise pairs of enzymes with matching DNA sequence specificity. The modification enzyme is a DNA methyltransferase that specifically methylates either adenosyl or cytosyl residues within the recognition sequence (the restriction site; RS), thus making DNA resistant to the restriction activity. The restriction enzyme is an endodeoxyribonuclease that cleaves DNA at a precise location within or around the recognition sequence, when this sequence is not methylated (Redaschi and Bickle 1996). These recognition sequences are symmetrical, comprising 4-8 specific base pairs, and cleavage and methylation occur symmetrically within the sequences. As a consequence, foreign double stranded DNA (dsDNA), unmethylated at the restriction sites recognized by the cell's RMS, is quickly degraded.

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Section: Roles Of Restriction Systems In Bacteriamentioning

confidence: 99%

Evolutionary Role of Restriction/Modification Systems as Revealed by Comparative Genome Analysis

Rocha¹

2001

Genome Research

107

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“…The adjustment seems not perfect; while the frequency of Lys, for example, increases from 20.3 in the host genes to 45.3 in the phage genes, there is no phage tRNA gene for Lys. Furthermore, the phage tRNAs may not be required for growth, LETTER TO THE EDITOR since another mycobacteriophage L5, which is closely related to D29, lacks the last two tRNAs in the D29 cluster (Fullner & Hatfull, 1997 …”

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confidence: 98%

Functional Role of Mycobacteriophage Transfer RNAs

Kunisawa¹

2000

Journal of Theoretical Biology

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“…Phages for mycobacteria were reported more than 7 decades ago (23,24). Some of the mycobacteriophages that have been studied extensively in mycobacterial research include the lytic phage TM4 (25,26) and the lysogenic phage L5 (27,28). Phage D29 is closely related to L5, although it is lytic in nature (29,30).…”

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confidence: 99%

Dynamics of Mycobacteriophage-Mycobacterial Host Interaction: Evidence for Secondary Mechanisms for Host Lethality

Samaddar

Grewal

Sinha

et al. 2016

Appl Environ Microbiol

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bMycobacteriophages infect mycobacteria, resulting in their death. Therefore, the possibility of using them as therapeutic agents against the deadly mycobacterial disease tuberculosis (TB) is of great interest. To obtain better insight into the dynamics of mycobacterial inactivation by mycobacteriophages, this study was initiated using mycobacteriophage D29 and Mycobacterium smegmatis as the phage-host system. Here, we implemented a goal-oriented iterative cycle of experiments on one hand and mathematical modeling combined with Monte Carlo simulations on the other. This integrative approach lends valuable insight into the detailed kinetics of bacterium-phage interactions. We measured time-dependent changes in host viability during the growth of phage D29 in M. smegmatis at different multiplicities of infection (MOI). The predictions emerging out of theoretical analyses were further examined using biochemical and cell biological assays. In a phage-host interaction system where multiple rounds of infection are allowed to take place, cell counts drop more rapidly than expected if cell lysis is considered the only mechanism for cell death. The phenomenon could be explained by considering a secondary factor for cell death in addition to lysis. Further investigations reveal that phage infection leads to the increased production of superoxide radicals, which appears to be the secondary factor. Therefore, mycobacteriophage D29 can function as an effective antimycobacterial agent, the killing potential of which may be amplified through secondary mechanisms.

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Mycobacteriophage L5 infection of Mycobacterium bovis BCG: implications for phage genetics in the slow‐growing mycobacteria

Cited by 43 publications

References 32 publications

Evolutionary Role of Restriction/Modification Systems as Revealed by Comparative Genome Analysis

Evolutionary Role of Restriction/Modification Systems as Revealed by Comparative Genome Analysis

Functional Role of Mycobacteriophage Transfer RNAs

Dynamics of Mycobacteriophage-Mycobacterial Host Interaction: Evidence for Secondary Mechanisms for Host Lethality

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