Figure 3.

Ribosome Splitting Precedes Ubiquitination

(A) Purified ³⁵S-labeled 80S F-VHP-β RNCs were subjected to a two-stage ubiquitination reaction with a preincubation (1^st) for 10 min with the indicated components, followed by another 10 min incubation (2^nd) without or with fraction 2. Total reaction products were analyzed by autoradiography.

(B) Schematic diagram illustrating the Mg²⁺-dependent dissociation of 80S RNC by eIF6.

(C) Ubiquitination reactions of ³⁵S-labeled 80S F-VHP-β RNCs at Mg²⁺ concentrations from 3.4 mM to 14.4 mM. All reactions contained eIF6 and fraction 2 of the ribosome salt wash.