March 25, 2003
Tuesday - 4:00 pm in Swain West 238
Speaker: Dr. Jose Carlos M. Mombach, Centro de Ciencias Exatas e Tecnologicas Unisinos
Images: image 1
Title: Essentiality and Damage in Metabolic Networks
Abstract:
The understanding of the architecture of physiological functions from annotated genome sequences is a major task for postgenomic biology. From the annotated genome sequence of the microbe Escherichia coli, we propose a general quantitative definition of enzyme importance in a metabolic network. Using a graph analysis of its metabolism, we determine a relation between the extent of the topological damage generated on the metabolic network by the deletion of an enzyme and the experimentally determined viability of the organism in the absence of that enzyme. We show that the network is robust and that the extent of the damage is related to enzyme importance. We predict that the a large fraction (91%) of enzymes causes a small damage when removed, while a small group (9%) can cause a high damage. Experimental results confirm that this group has the majority of essential enzymes. The results may be a universal property of the metabolic networks.