Loading...
Please wait, while we are loading the content...
Similar Documents
Network Motifs Provide Signatures That Characterize Metabolism and Produce Novel Insights into the Evolutionary History of the Eukaryotic Cell.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Shellman, Erin R. |
| Copyright Year | 2012 |
| Abstract | Network Motifs Provide Signatures that Characterize Metabolism by Erin Rachael Shellman Chairs: Doctor Charles Burant and Professor Santiago Schnell A motif is a small, repeated pattern that is over-represented in a network compared to its abundance in a collection of random graphs. Motifs are of chief interest in network theory and systems biology because their over-expression may determine the topological properties that give rise to dynamic behaviors in biological systems. Motifs also provide novel functional evidence that can help unravel mechanisms of molecular evolution. In this work, we analyze metabolic network motifs, where metabolites are represented by nodes and biochemical associations are represented by edges. We find that metabolic network motifs can be characterized by their enzyme class associations and therefore, their biochemical functionality. Further, we demonstrate that cellular organelles display motif distributions that can be distinct and likely reflect the organelle’s distinct metabolic role in the cell. We follow this analysis by assessing the relationship between motif participation and the property of tolerance to random component failure in the E. coli metabolic network. We find that the metabolic network displays higher levels of failure tolerance than seen in Erdős-Rényi random graphs, and that some motifs have unique structural properties in metabolism. Finally, we apply the methodology of motif mining and analysis to assess specific hypotheses xii of Eukaryotic organelle evolution. Specifically, we present novel evidence suggesting that an α-proteobacterium may not have been the ancestor of modern mitochondria. We independently validate this result using phylogenetic analysis and find that mitochondrial genomes tend to fall within the same clades as δand -proteobacteria. Based on this validation we propose a new hypothesis that modern mitochondria are not derived from α-proteobacteria, but are instead derived from a member of the δor -proteobacterial families. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://deepblue.lib.umich.edu/bitstream/handle/2027.42/96065/shellman_1.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
