Evolutionary Implications of Protein Domain Network in Eukaryotes

Complex network theory is utilized to explore the implication of protein domain content on evolution of eukaryotes. Comparative analysis of domains and their combination networks of eukaryotic organisms ranging over different phylogenetic groups demonstrate that: (1) topological features of domain combination network are correlated with organismal complexity; (2) globally central domains, defined by k-core decomposition method, are more structurally flexible than peripheral ones in terms of statistical e-value scores. We hypothesize that it might be flexibility under nature selection to make promiscuous domains more capable to incorporate other domains in order to achieve functional complexity in higher organisms.