Figure 3.

Analysis of side views of GroEL·GroES complexes in the presence of denatured MBP by electron microscopy and image analysis. (A–D) The four major structural classes of GroE complexes in the sample (498 particles) based on the first two eigenvectors. (A) Empty bullet (24%). (B) Football with one MBP bound (23%). (C) Bullet with MBP bound inside (25%). (D) Footballs with two MBPs bound (28%). The eigenvector–eigenvalue analysis of the sample is documented in E–K. (E) Reference particle for the analysis (the average of all side views). (F) The most significant difference (eigenvector) between the particles. In H and I, this difference is depicted in terms of different classes of particles (bullets and footballs). (G) The second major difference obtained and (J and K) the two corresponding classes of averages differing in the presence of stain-excluding mass inside the GroEL·GroES complex.