Fig. 9

The relationship between processivity and degradation timing or dynamics. a A modified one-substrate model to simulate processivity. The system starts with AS0 as the only component. Each AS complex can either obtain one ubiquitin or dissociate into A and S. b Graphs at left show the amounts of each species as the system approaches steady state over time. The plot on the right shows the average number of ubiquitins per substrate, calculated as follows: when all substrates have dissociated from APC/C, no more reactions occur and the system reaches steady state, the total number of ubiquitins attached to all substrates is divided by the total number of substrates. c T95 and Td were calculated with the one-substrate system illustrated in Fig. 2. The T95 plot shows the same data as in Fig. 4a, color-coded to provide more detail and to facilitate comparison with panel b above. APC/C anaphase-promoting complex/cyclosome