Table 2.

Procapsid scaffolding protein content measured from three-dimensional reconstructions

Procapsid sourceScaffold mass (MDa)aScaffold protein copy no.bReference
Assembled in vitro in cell extracts66.4–76.71,967–2,272 46
Assembled in vitro from purified proteins75.81,902 25
Isolated fromm100- infected cells63.0–69.91,866–2,070This study
  • a Determined by integration of radial electron density profiles such as those shown in Fig. 4. Ranges of values are shown for reconstructions in which there was uncertainty regarding the baseline in the radial density profile. The scaffold mass was calibrated relative to the shell mass, which was assumed to be 180.9 MDa (i.e., 960, 320, and 640 copies of VP5, VP19C, and VP23, respectively).

  • b Calculated by assuming the following molecular weights: for preVP22a, 33,760 (cell extract andm100 procapsids); for pUL80.5-H, 39,855 (purified protein procapsids).