Figure 1. Identification and characterization of the ESCRT-I core.
A. Domain structure of ESCRT-I and complexes used in this study. B. Gel filtration of the EIΔUEV-A construct. C. Sedimentation velocity analysis of the 190 kDa peak obtained by gel filtration of the EIΔUEV-A construct in (B), showing the presence of two species. D. Sedimentation equilibrium analysis in terms of a monomer-dimer equilibrium of the EIΔUEV-A construct in (B) for data collected at 10 (blue), 12 (green) and 16 (red) krpm. The solid lines show the best-fit global analysis. Best-fit residuals are shown above the plot. E. Analysis of a partial endoproteinase Glu-C digest of EIΔUEV-B by gel filtration and protein sequencing showing the identification of Vps28 core boundaries. Additional analyses of Glu-C and tryptic digests were used to determine the core boundaries of Vps23 and Vps37 (not shown). F. Sedimentation equilibrium analysis of the core construct showing a single species consistent with a 1:1:1 complex. Data were collected at 11 (blue), 14 (green) and 17 (red) krpm for loading A280 of 0.50 (left), 0.41 (center) and 0.71 (right). The solid lines show the best-fit global analysis in terms of a single ideal solute, with the corresponding residuals shown in the panels above the plot.
