Folding and self-assembly of a small heterotetramer.

Designed miniproteins offer a possibility to study folding and association of protein complexes, both experimentally and in silico. Using replica exchange molecular dynamics and the coarse-grain UNRES force field, we have simulated the folding and self-assembly of the heterotetramer BBAThet1, comparing it with that of the homotetramer BBAT1 which has the same size and ββα-fold. For both proteins, association of the tetramer precedes and facilitates folding of the individual chains.