Abstract: Network based on protein-protein interaction (PPI) had a obvious modular characteristics, which played an important role in predicting protein functions and explaining specific biological processes. Network motif was an important topology for the evolution of complex networks. It represented important functional units in complex systems and had the characteristics of evolutionary conservation. We proposed a new protein complex recognition algorithm based on network motif as the core node group.  According to the topological characteristics of the PPI network, the algorithm took  motifs as central structures of the protein complexes, and expanded the two-layer nodes based on central structure, which could accurately and effectively identify protein complexes. The 2D network of the protein complexes was transformed into 3D network, so as to show  the structural characteristics of the protein complexes more intuitively and clearly. The experimental results verify the effectiveness and feasibility of the algorithm.

Key words: protein-protein interaction network, network motif, protein complex, central structure