FIGURE 8.

The interface between the apical domains of the C and D subunit (see text). The H helices of GroEL are colored yellow, the I helices are green, loop 310–315 is orange, loop 225–230 is light blue, and loop 252–256 is purple; the rest of GroEL is blue. Subunit C is shown as a ribbon diagram with the polar and charged side chains of loops 225–230 and 252–256 of subunit C as stick models; Arg-231 is shown as a yellow stick model to indicate the closeness of this residue to the H helix (analogous to Fig. 7). For subunit D the solvent-accessible surface is shown in blue. Rhodanese is shown in red, hydrogen bonds between GroEL residues 225–231 and rhodanese are indicated by the orange dotted lines. GroEL is viewed from the top; the viewing angle is identical to that of Fig. 2.