Figure 6. Application to an experimental high-resolution data set.
A. Cross-section of the unfiltered and unsharpened papillomavirus map, generated by FREALIGN using the methods described by Wolf et al. (2010).
B. Core mask function for this procedure was defined by first applying a 15 Å low-pass-filter to the reconstruction in panel A. The core mask was then defined by choosing a binary cutoff threshold such that 1% of the total reconstruction volume was included (volume occupied by the virus shell was ~15% of the reconstruction volume).
C. Results of our estimation procedure for fparticle , using the post-processing SPW filter.
D. Comparison of post-processing filter functions. The solid curve depicts the FOM weights used by Wolf et al. (2010) following the scheme of Rosenthal and Henderson (2003), using Eq. (11). The dashed curve depicts the SPW post-processing weights obtained through Eq. (9).
E. Isosurface of the density map from A, depicting an L1 pentamer on the surface of the capsid.
F. Isosurface from E, superposed with semitransparent isosurface of the same map (gray), low-pass-filtered to 15 Å and thresholded such that the volume enclosed by the surface is equivalent to fparticle = 0.075, the value identified by our estimation procedure in panel C.