Institute of Information Science Academia Sinica
Topic: TIGP -- Evolution of domain architectures and catalytic functions of enzymes in metabolic systems
Speaker: Dr. Chen-Hsiang Yeang (Institute of Statistical Science, Academia Sinica)
Date: 2012-05-03 (Thu) 14:00 – 15:10
Location: Auditorium 106 at new IIS Building
Host: Chun-Nan Hsu


Domain architectures and catalytic functions of enzymes constitute the centerpieces of a metabolic network.  These types of information are formulated as a two-layered network consisting of domains, proteins and reactions -- a domain-protein-reaction network.  Despite the rich literature of each individual aspect, simultaneous characterization of both features and depiction of their evolution in multiple metabolic systems have not been previously pursued.  We propose an algorithm to reconstruct the evolutionary history of domain-protein-reaction networks across multiple species and categorize the mechanisms of metabolic systems evolution in terms of network changes.  Accuracy of the reconstruction algorithm is confirmed by predictions on simulated data and cross validations on real metabolic networks.  The reconstructed history reveals distinct patterns of evolutionary mechanisms between prokaryotic and eukaryotic networks.  While the evolutionary mechanisms in early ancestors of prokaryotes and eukaryotes are quite similar, more novel and duplicated domain compositions with identical catalytic functions arise along the eukaryotic lineage.  In contrast, prokaryotic enzymes become more versatile by catalyzing multiple reactions with similar chemical operations.  Moreover, different metabolic pathways are enriched with distinct network evolution mechanisms.  These results shed new lights on the evolution of metabolic systems.