Phage DNA packaging

Fujisawa, Hisao; Morita, Miyo Terao

doi:10.1046/j.1365-2443.1997.1450343.x

Cited by 169 publications

(165 citation statements)

References 42 publications

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“…Dynamically, the presence of knots and their possible effects on the mobility of biopolymers are essential to the understanding of their behaviour in vivo or, e.g., as studied by electrophoresis in vitro [25]. A similar role is played by topological effects for the translocation of viral and nonviral proteins [12,26], and packaging of DNA [27]. In supramolecular chemistry, molecules with identical bond sequence but different topology can be produced which exhibit different physical properties, and mechanically linked molecules open up new vistas in information processing or nano-engineering [28,29,30].…”

Section: Introductionmentioning

confidence: 99%

Tightness of slip-linked polymer chains

et al. 2002

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We study the interplay between entropy and topological constraints for a polymer chain in which sliding rings (slip-links) enforce pair contacts between monomers. These slip-links divide a closed ring polymer into a number of sub-loops which can exchange length between each other. In the ideal chain limit, we find the joint probability density function for the sizes of segments within such a sliplinked polymer chain (paraknot). A particular segment is tight (small in size) or loose (of the order of the overall size of the paraknot) depending on both the number of slip-links it incorporates and its competition with other segments. When self-avoiding interactions are included, scaling arguments can be used to predict the statistics of segment sizes for certain paraknot configurations.

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Section: Introductionmentioning

confidence: 99%

Tightness of slip-linked polymer chains

et al. 2002

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“…The packaging machinery is also located at this vertex, forming a portal by incorporating terminases that select, cleave, and push the DNA inside the viral head through the connector. More specifically, the T7 prohead interacts with terminase gp19 to package the complex built by the DNA and terminase gp18 after cutting the unit length DNA from the replicating concatemers (29). The maturation of T7 involves the disappearance of the scaffolding protein, major rearrangements of the core, the incorporation of the tail, and a dramatic transformation of the shell, which undergoes a radial expansion.…”

mentioning

confidence: 99%

Molecular Rearrangements Involved in the Capsid Shell Maturation of Bacteriophage T7

Ionel

Velázquez-Muriel

Luque

et al. 2011

Journal of Biological Chemistry

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Maturation of dsDNA bacteriophages involves assembling the virus prohead from a limited set of structural components followed by rearrangements required for the stability that is necessary for infecting a host under challenging environmental conditions. Here, we determine the mature capsid structure of T7 at 1 nm resolution by cryo-electron microscopy and compare it with the prohead to reveal the molecular basis of T7 shell maturation. The mature capsid presents an expanded and thinner shell, with a drastic rearrangement of the major protein monomers that increases in their interacting surfaces, in turn resulting in a new bonding lattice. The rearrangements include tilting, in-plane rotation, and radial expansion of the subunits, as well as a relative bending of the A-and P-domains of each subunit. The unique features of this shell transformation, which does not employ the accessory proteins, inserted domains, or molecular interactions observed in other phages, suggest a simple capsid assembling strategy that may have appeared early in the evolution of these viruses.

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“…In lambdoid bacteriophages, packaging of the phage genome into a viable phage particle needs a concatemer form, in which phage DNA units are joined together in a head-to-tail manner (Fujisawa and Morita 1997). Formation of the concatemer is blocked by the RecBCD DNase of the host E. coli, which degrades nonself DNA but repairs self DNA marked by an ID sequence (Handa et al 1997(Handa et al , 2000.…”

Section: Discussionmentioning

confidence: 99%

Evolution of DNA Double-Strand Break Repair by Gene Conversion: Coevolution Between a Phage and a Restriction-Modification System

et al. 2007

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The necessity to repair genome damage has been considered to be an immediate factor responsible for the origin of sex. Indeed, attack by a cellular restriction enzyme of invading DNA from several bacteriophages initiates recombinational repair by gene conversion if there is homologous DNA. In this work, we modeled the interaction between a bacteriophage and a bacterium carrying a restriction enzyme as antagonistic coevolution. We assume a locus on the bacteriophage genome has either a restriction-sensitive or a restriction-resistant allele, and another locus determines whether it is recombination/repair proficient or defective. A restriction break can be repaired by a co-infecting phage genome if one of them is recombination/ repair proficient. We define the fitness of phage (resistant/sensitive and repair-positive/-negative) genotypes and bacterial (restriction-positive/-negative) genotypes by assuming random encounter of the genotypes, with given probabilities of single and double infections, and the costs of resistance, repair, and restriction. Our results show the evolution of the repair allele depends on b 1 =b 0 , the ratio of the burst size b 1 under damage to host cell physiology induced by an unrepaired double-strand break to the default burst size b 0 . It was not until this effect was taken into account that the evolutionary advantage of DNA repair became apparent.

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Phage DNA packaging

Cited by 169 publications

References 42 publications

Tightness of slip-linked polymer chains

Tightness of slip-linked polymer chains

Molecular Rearrangements Involved in the Capsid Shell Maturation of Bacteriophage T7

Evolution of DNA Double-Strand Break Repair by Gene Conversion: Coevolution Between a Phage and a Restriction-Modification System

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