The N-terminus modulates human Caf1 activity, structural stability and aggregation.

Caf1 is a deadenylase component of the CCR4-Not complex. Here we found that the removal of the N-terminus resulted in a 30% decrease in human Caf1 (hCaf1) activity, but had no significant influence on main domain structure. The removal of the N-terminus led to a decrease in the thermal stability, while the existence of the N-terminus promoted hCaf1 thermal aggregation. Homology modeling indicated that the N-terminus had a potency to form a short α-helix interacted with the main domain. Thus the N-terminus played a role in modulating hCaf1 activity, stability and aggregation.