Summary information and primary citation

PDB-id
1pfi; SNAP-derived features in text and JSON formats; DNAproDB
Class
virus
Method
fiber diffraction
Summary
Pf1 virus structure: helical coat protein and DNA with paraxial phosphates
Reference
Liu DJ, Day LA (1994): "Pf1 virus structure: helical coat protein and DNA with paraxial phosphates." Science, 265, 671-674.
Abstract
The helical path of the DNA in filamentous bacteriophage Pf1 was deduced from different kinds of existing structural information, including results from x-ray fiber diffraction. The DNA has the same pitch, 16 angstroms, as the surrounding helix of protein subunits; the rise and rotation per nucleotides are 6.1 angstroms and 132 degrees, respectively; and the phosphates are 2.5 angstroms from the axis. The DNA in Pf1 is, therefore, the most extended and twisted DNA structure known. On the basis of the DNA structure and extensive additional information about the protein, a model of the virion is proposed. In the model, the DNA bases reach out, into the protein, and the lysine and arginine side chains reach in, between the DNA bases, to stabilize the paraxial phosphate charges; the conformation of the protein subunit is a combination of alpha and 3(10) helices.

Cartoon-block schematics in six views (download the tarball)

PyMOL session file Download PDB file View in 3Dmol.js