Low degree metabolites explain essential reactions and enhance modularity in biological networks

Background: Recently there has been a lot of interest in identifying modules at the level of genetic and metabolic networks of organisms, as well as in identifying single genes and reactions that are essential for the organism. A goal of computational and systems biology is to go beyond identification towards an explanation of specific modules and essential genes and reactions in terms of specific structural or evolutionary constraints. Results: In the metabolic networks of Escherichia coli, Saccharomyces cerevisiae and Staphylococcus aureus, we identified metabolites with a low degree of connectivity, particularly those that are produced and/or consumed in just a single reaction. Using flux balance analysis (FBA) we also determined reactions essential for growth in these metabolic networks. We find that most reactions identified as essential in these networks turn out to be those involving the production or consumption of low degree metabolites. Applying graph theoretic methods to th...

• Type: Journal
• Year: 2006
• Where: BMCBI
• Authors: Areejit Samal, Shalini Singh, Varun Giri, Sandeep Krishna, Nandula Raghuram, Sanjay Jain
• Keywords: BMCBI 2006, Low Degree, Low Degree Metabolites, Metabolic Networks