Early stage evolution in metabolic related protein interaction network

Protein-protein interaction network provides valuable information in adaptation and evolution of living organisms. Since metabolism is one of the most fundamental processes in the early formation of live organism, we selected metabolic proteins from MIPS function category and constructed metabolic-related protein-protein interaction network. The network has scale-free and hierarchical properties as if most biological networks do. It is relatively difficult to identify whole extension patterns in yeast protein interaction network. We, therefore, focused on the early stage of evolution in the network. As examined attachment pattern of new protein, we analyzed early stage of the extension patterns in the network. Our results elucidate how valuable information obtains from complex network and provide insight about evolution processes of the network in yeast.