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Viral nanomotors for packaging of dsDNA and dsRNA.

Guo P, Lee TJ - Mol. Microbiol. (2007)

Bottom Line: This entropically unfavourable DNA or RNA packaging is accomplished by an ATP-driven viral nanomotor, which is mainly composed of two components, the oligomerized channel and the packaging enzymes.The novel and ingenious configuration of these nanomotors has inspired the development of biomimetics for nanodevices.Advances in structural and functional studies have increased our understanding of the molecular basis of biological movement to the point where we can begin thinking about possible applications of the viral DNA packaging motor in nanotechnology and medical applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Comparative Pathobiology and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA. guop@purdue.edu

ABSTRACT
While capsid proteins are assembled around single-stranded genomic DNA or RNA in rod-shaped viruses, the lengthy double-stranded genome of other viruses is packaged forcefully within a preformed protein shell. This entropically unfavourable DNA or RNA packaging is accomplished by an ATP-driven viral nanomotor, which is mainly composed of two components, the oligomerized channel and the packaging enzymes. This intriguing DNA or RNA packaging process has provoked interest among virologists, bacteriologists, biochemists, biophysicists, chemists, structural biologists and computational scientists alike, especially those interested in nanotechnology, nanomedicine, AAA+ family proteins, energy conversion, cell membrane transport, DNA or RNA replication and antiviral therapy. This review mainly focuses on the motors of double-stranded DNA viruses, but double-stranded RNA viral motors are also discussed due to interesting similarities. The novel and ingenious configuration of these nanomotors has inspired the development of biomimetics for nanodevices. Advances in structural and functional studies have increased our understanding of the molecular basis of biological movement to the point where we can begin thinking about possible applications of the viral DNA packaging motor in nanotechnology and medical applications.

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Viral DNA packaging motors. A. The portal or the connector structure of bacteriophage ε15 (a) (Jiang et al., 2006), T3 (b) (Valpuesta et al., 2000), T7 (c) (Agirrezabala et al., 2005) and P22 (d) (Lander et al., 2006). B. The assembly pathway of λ terminase and the structure of the related DNA substrate (Maluf et al., 2006; Ortega and Catalano, 2006). C. Similarity between two models; the phi29 DNA packaging motor (a) and PCNA/clamp-loader complex (b) (Lee and Guo, 2006). Figures were adapted with permission from the authors and from Elsevier, American Association for the Advancement of Science, and American Chemical Society to the respective citation.
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fig01: Viral DNA packaging motors. A. The portal or the connector structure of bacteriophage ε15 (a) (Jiang et al., 2006), T3 (b) (Valpuesta et al., 2000), T7 (c) (Agirrezabala et al., 2005) and P22 (d) (Lander et al., 2006). B. The assembly pathway of λ terminase and the structure of the related DNA substrate (Maluf et al., 2006; Ortega and Catalano, 2006). C. Similarity between two models; the phi29 DNA packaging motor (a) and PCNA/clamp-loader complex (b) (Lee and Guo, 2006). Figures were adapted with permission from the authors and from Elsevier, American Association for the Advancement of Science, and American Chemical Society to the respective citation.

Mentions: The bacteriophage connector is composed of 12 copies of single protein and forms a six- and 12-fold symmetric ring attached to a fivefold symmetric vertex of the outer shell that leads to a symmetry mismatch between the capsid and the portal. A similar dodecameric portal has also been found in HSV type 1 (Newcomb et al., 2001; Trus et al., 2004). As proposed (Hendrix, 1978), such a symmetric mismatch would enhance the free energy (ΔG) to facilitate the relative rotation of the two rings of the portal during DNA packaging, although it is still unclear whether the portal rotates during DNA translocation. The portal obviously plays an important role in packaging, as amino acid substitutions or N-terminal extensions on the portal protein dramatically block the packaging. Translocation of dsDNA molecules during maturation or infection occurs through a 3–4 nm channel that runs along the connector. The 3D structures of several isolated recombinant connectors have been determined by Cryo-EM (Jimenez et al., 1986; Lurz et al., 2001; Guasch et al., 2002; Fokine et al., 2004; Trus et al., 2004; Agirrezabala et al., 2005; Jiang et al., 2006; Lander et al., 2006) (Fig. 1A).


Viral nanomotors for packaging of dsDNA and dsRNA.

Guo P, Lee TJ - Mol. Microbiol. (2007)

Viral DNA packaging motors. A. The portal or the connector structure of bacteriophage ε15 (a) (Jiang et al., 2006), T3 (b) (Valpuesta et al., 2000), T7 (c) (Agirrezabala et al., 2005) and P22 (d) (Lander et al., 2006). B. The assembly pathway of λ terminase and the structure of the related DNA substrate (Maluf et al., 2006; Ortega and Catalano, 2006). C. Similarity between two models; the phi29 DNA packaging motor (a) and PCNA/clamp-loader complex (b) (Lee and Guo, 2006). Figures were adapted with permission from the authors and from Elsevier, American Association for the Advancement of Science, and American Chemical Society to the respective citation.
© Copyright Policy
Related In: Results  -  Collection

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fig01: Viral DNA packaging motors. A. The portal or the connector structure of bacteriophage ε15 (a) (Jiang et al., 2006), T3 (b) (Valpuesta et al., 2000), T7 (c) (Agirrezabala et al., 2005) and P22 (d) (Lander et al., 2006). B. The assembly pathway of λ terminase and the structure of the related DNA substrate (Maluf et al., 2006; Ortega and Catalano, 2006). C. Similarity between two models; the phi29 DNA packaging motor (a) and PCNA/clamp-loader complex (b) (Lee and Guo, 2006). Figures were adapted with permission from the authors and from Elsevier, American Association for the Advancement of Science, and American Chemical Society to the respective citation.
Mentions: The bacteriophage connector is composed of 12 copies of single protein and forms a six- and 12-fold symmetric ring attached to a fivefold symmetric vertex of the outer shell that leads to a symmetry mismatch between the capsid and the portal. A similar dodecameric portal has also been found in HSV type 1 (Newcomb et al., 2001; Trus et al., 2004). As proposed (Hendrix, 1978), such a symmetric mismatch would enhance the free energy (ΔG) to facilitate the relative rotation of the two rings of the portal during DNA packaging, although it is still unclear whether the portal rotates during DNA translocation. The portal obviously plays an important role in packaging, as amino acid substitutions or N-terminal extensions on the portal protein dramatically block the packaging. Translocation of dsDNA molecules during maturation or infection occurs through a 3–4 nm channel that runs along the connector. The 3D structures of several isolated recombinant connectors have been determined by Cryo-EM (Jimenez et al., 1986; Lurz et al., 2001; Guasch et al., 2002; Fokine et al., 2004; Trus et al., 2004; Agirrezabala et al., 2005; Jiang et al., 2006; Lander et al., 2006) (Fig. 1A).

Bottom Line: This entropically unfavourable DNA or RNA packaging is accomplished by an ATP-driven viral nanomotor, which is mainly composed of two components, the oligomerized channel and the packaging enzymes.The novel and ingenious configuration of these nanomotors has inspired the development of biomimetics for nanodevices.Advances in structural and functional studies have increased our understanding of the molecular basis of biological movement to the point where we can begin thinking about possible applications of the viral DNA packaging motor in nanotechnology and medical applications.

View Article: PubMed Central - PubMed

Affiliation: Department of Comparative Pathobiology and Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA. guop@purdue.edu

ABSTRACT
While capsid proteins are assembled around single-stranded genomic DNA or RNA in rod-shaped viruses, the lengthy double-stranded genome of other viruses is packaged forcefully within a preformed protein shell. This entropically unfavourable DNA or RNA packaging is accomplished by an ATP-driven viral nanomotor, which is mainly composed of two components, the oligomerized channel and the packaging enzymes. This intriguing DNA or RNA packaging process has provoked interest among virologists, bacteriologists, biochemists, biophysicists, chemists, structural biologists and computational scientists alike, especially those interested in nanotechnology, nanomedicine, AAA+ family proteins, energy conversion, cell membrane transport, DNA or RNA replication and antiviral therapy. This review mainly focuses on the motors of double-stranded DNA viruses, but double-stranded RNA viral motors are also discussed due to interesting similarities. The novel and ingenious configuration of these nanomotors has inspired the development of biomimetics for nanodevices. Advances in structural and functional studies have increased our understanding of the molecular basis of biological movement to the point where we can begin thinking about possible applications of the viral DNA packaging motor in nanotechnology and medical applications.

Show MeSH
Related in: MedlinePlus