Dependency map of proteins in the small ribosomal subunit

The assembly of the ribosome has recently become an interesting target
 for antibiotics in several bacteria. In this work, we extended an
 analytical procedure to determine native state fluctuations and contact
 breaking to investigate the protein stability dependence in the 30S
 small ribosomal subunit of Thermus thermophilus. We determined the
 causal influence of the presence and absence of proteins in the 30S
 complex on the binding free energies of other proteins. The predicted
 dependencies are in overall agreement with the experimentally determined
 assembly map for another organism, Escherichia coli. We found that
 the causal influences result from two distinct mechanisms: one is
 pure internal energy change, the other originates from the entropy
 change. We discuss the implications on how to target the ribosomal
 assembly most effectively by suggesting six proteins as targets for
 mutations or other hindering of their binding. Our results show that
 by blocking one out of this set of proteins, the association of other
 proteins is eventually reduced, thus reducing the translation efficiency
 even more. We could additionally determine the binding dependency
 of THX peptide not present in the ribosome of E. coli and suggest
 its assembly path