Work

A Structural Model for the Single-Stranded DNA Genome of Filamentous Bacteriophage Pf1

Year: 2010

Type: article

Abstract: The filamentous bacteriophage Pf1, which infects strain PAK of Pseudomonas aeruginosa, is a flexible filament ( approximately 2000 x 6.5 nm) consisting of a covalently closed DNA loop of 7349 nucleotides sheathed by 7350 copies of a 46-residue alpha-helical subunit. The subunit alpha-helices, which are inclined at a small average angle ( approximately 16 degrees ) from the virion axis, are arranged compactly around the DNA core. Orientations of the Pf1 DNA nucleotides with respect to the filament axis are not known. In this work we report and interpret the polarized Raman spectra of oriented Pf1 filaments. We demonstrate that the polarizations of DNA Raman band intensities establish that the nucleotide bases of packaged Pf1 DNA are well ordered within the virion and that the base planes are positioned close to parallel to the filament axis. The present results are combined with a previously proposed projection of the intraviral path of Pf1 DNA [Liu, D. J., and Day, L. A. (1994) Science 265, 671-674] to develop a novel molecular model for the Pf1 assembly.

Source: Biochemistry

DOI: 10.1021/bi901323a

Authors: Masamichi Tsuboi, Masaru Tsunoda, Stacy A. Overman, James M. Benevides, George J. Thomas

Institutions: IRYO Sosei University, University of Missouri–Kansas City

Language: English

Topic: Spectroscopy Techniques in Biomedical and Chemical Research

Subfield: Biophysics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Awards: Molecular Structure and Interactions of Viruses, Structures, Interactions and Dynamics of Nucleic Acids