Viruses 2010, 2(9), 1821-1843; doi:10.3390/v2091821
Article

A Hypothesis for Bacteriophage DNA Packaging Motors

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Received: 4 June 2010; in revised form: 12 August 2010 / Accepted: 18 August 2010 / Published: 26 August 2010
(This article belongs to the Special Issue Bacteriophage Assembly)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The hypothesis is presented that bacteriophage DNA packaging motors have a cycle comprised of bind/release thermal ratcheting with release-associated DNA pushing via ATP-dependent protein folding. The proposed protein folding occurs in crystallographically observed peptide segments that project into an axial channel of a protein 12-mer (connector) that serves, together with a coaxial ATPase multimer, as the entry portal. The proposed cycle begins when reverse thermal motion causes the connector’s peptide segments to signal the ATPase multimer to bind both ATP and the DNA molecule, thereby producing a dwell phase recently demonstrated by single-molecule procedures. The connector-associated peptide segments activate by transfer of energy from ATP during the dwell. The proposed function of connector/ATPase symmetry mismatches is to reduce thermal noise-induced signaling errors. After a dwell, ATP is cleaved and the DNA molecule released. The activated peptide segments push the released DNA molecule, thereby producing a burst phase recently shown to consist of four mini-bursts. The constraint of four mini-bursts is met by proposing that each mini-burst occurs via pushing by three of the 12 subunits of the connector. If all four mini-bursts occur, the cycle repeats. If the mini-bursts are not completed, a second cycle is superimposed on the first cycle. The existence of the second cycle is based on data recently obtained with bacteriophage T3. When both cycles stall, energy is diverted to expose the DNA molecule to maturation cleavage.
Keywords: bacteriophage structure; biological energy transduction; biological signal noise; cryo-electron microscopy; single-molecule analysis
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MDPI and ACS Style

Serwer, P. A Hypothesis for Bacteriophage DNA Packaging Motors. Viruses 2010, 2, 1821-1843.

AMA Style

Serwer P. A Hypothesis for Bacteriophage DNA Packaging Motors. Viruses. 2010; 2(9):1821-1843.

Chicago/Turabian Style

Serwer, Philip. 2010. "A Hypothesis for Bacteriophage DNA Packaging Motors." Viruses 2, no. 9: 1821-1843.


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