  We study the correlation between the codon usage bias of genetic sequences
and the network features of protein-protein interaction (PPI) in bacterial
species. We use PCA techniques in the space of codon bias indices to show that
genes with similar patterns of codon usage have a significantly higher
probability that their encoded proteins are functionally connected and
interacting. Importantly, this signal emerges when multiple aspects of codon
bias are taken into account at the same time. The present study extends our
previous observations on E.Coli over a wide set of 34 bacteria. These findings
could allow for future investigations on the possible effects of codon bias on
the topology of the PPI network, with the aim of improving existing
bioinformatics methods for predicting protein interactions.
