Matching Electrostatic Charge between DNA and Coat Protein in Filamentous Bacteriophage. Fibre Diffraction of Charge-deletion Mutants

Role of Capsid Structure and Membrane Protein Processing in Determining the Size and Copy Number of Peptides Displayed on the Major Coat Protein of Filamentous Bacteriophage

“…Diffraction patterns were collected on Station 7.2 of the synchrotron at the CLRC Daresbury Laboratory, using a wavelength of 1.488 Å and diffraction data were calibrated and processed using the programs from the CCP13 suite (Symmons et al, 1995;and R. Denny, personal communication).…”

“…The major coat protein contains 50 amino acid residues and is largely a-helical; in the virion the pVIII subunits form a shingled, helical array, with the long axes of the a-helices making a small angle with the axis of the virus particle (Marvin, 1990;Glucksman et al, 1992;Marvin et al, 1994). The negatively charged Nterminal regions are exposed on the outer surface of the virion, whereas the C-terminal segments line the cylindrical hole generated by the protein sheath, in which their positively charged side-chains neutralize the negatively charged phosphodiester links of the DNA (Symmons et al, 1995).…”

The molecular structure and structural transition of the α-helical capsid in filamentous bacteriophage Pf1

“…not J 0 ) includes both complex conjugates, and to calculate electron density it is necessary to correct for this effect, as pointed out by Symmons et al (1995). The reason for this correction can be illustrated by a simple thought experiment.…”

Characterization of the Cholesteric Phase of Filamentous Bacteriophage fd for Molecular Alignment

“…The coat proteins in the phage virions are arranged in a right-handed helical array with five subunits in the 16.26-Å axial repeat (15). The length of the packaged single-stranded DNA genome in the mutant phage is not changed compared to the wild-type; it simply is more stretched out inside a longer virion (16). Likewise, Pf1 closely resembles fd in morphology; it exhibits an identical particle diameter of about 6.6 nm, the mass per unit length is very similar (18,300 Da /nm for fd and 18,600 Da/nm for Pf1) and has a similar pI value (4.0 for fd and 4.2 for Pf1), and the charge density for both phages is identical over the pH 7-8 interval (17).…”