Fig. 5: Mechanism of substrate extraction and translocation by Drg1.

a, Major steps of Rlp24 extraction: recruitment of Drg1 to the particle, initial substrate capture, insertion into the pore and processive translocation. Filtered maps are shown for simplification. b, Structural basis for substrate translocation. The same conformational changes are shown from three different views in parallel: side, top and cross-section. ‘P’ denotes the seam protomer. Nucleotide loading in the current seam protomer transmits conformational changes to the adjacent protomers (P+1 and P+2) (see also Supplementary Movie 1). Two terminal frames from the 3DVA (7-Å filter resolution) are shown. c, Motion transmission between adjacent protomers occurs through the helical subdomain to the next clockwise AAA domain, as exemplified for D1. A short helix (residues 269–273, blue) of the α/β domain is hooked into the helical domain of the adjacent protomer, which coordinates movements of both domains. The nucleotide (yellow) is positioned between the two subdomains.