Title
The Activity Reaction Core And Plasticity Of Metabolic Networks
Abstract
Understanding the system-level adaptive changes taking place in an organism in response to variations in the environment is a key issue of contemporary biology. Current modeling approaches, such as constraint-based flux-balance analysis, have proved highly successful in analyzing the capabilities of cellular metabolism, including its capacity to predict deletion phenotypes, the ability to calculate the relative flux values of metabolic reactions, and the capability to identify properties of optimal growth states. Here, we use flux-balance analysis to thoroughly assess the activity of Escherichia coli, Helicobacter pylori, and Saccharomyces cerevisiae metabolism in 30,000 diverse simulated environments. We identify a set of metabolic reactions forming a connected metabolic core that carry non-zero fluxes under all growth conditions, and whose flux variations are highly correlated. Furthermore, we find that the enzymes catalyzing the core reactions display a considerably higher fraction of phenotypic essentiality and evolutionary conservation than those catalyzing noncore reactions. Cellular metabolism is characterized by a large number of species-specific conditionally active reactions organized around an evolutionary conserved, but always active, metabolic core. Finally, we find that most current antibiotics interfering with bacterial metabolism target the core enzymes, indicating that our findings may have important implications for antimicrobial drug- target discovery.
Year
DOI
Venue
2005
10.1371/journal.pcbi.0010068
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
metabolic network,quantitative method,enzyme,drug targeting,neural network,escherichia coli,evolutionary conservation
Microbial metabolism,Conserved sequence,Enzyme,Phenotype,Biology,Metabolic network,Metabolism,Bioinformatics,Saccharomyces cerevisiae,Genetics,Organism
Journal
Volume
Issue
ISSN
1
7
1553-7358
Citations 
PageRank 
References 
20
3.87
2
Authors
3
Name
Order
Citations
PageRank
Eivind Almaas1508.30
Zoltán N. Oltvai212110.87
Albert-lászló Barabási346491107.35