Genome-scale metabolic network reconstruction is important for understanding cellular behaviors in a systems view.
Converting the reconstruction into a mathematical model enables researchers to analyze cell behaviors in response to changing environments by using constraint-based flux balance analysis (FBA) tools, such as COBRA [1].
With the growing availability of complete microbial genomes, the number of genome-scale metabolic networks is expected to increase rapidly.
However, the number of genome-scale metabolic models follows in single-digit percentage of the number of sequenced genomes due to the difficulties in network reconstruction [2].
Availabe genome-scale metabolic network reconstructions were collected and listed in Palsson's Systems Biology Research Group.
Here, we took the adavantage of these reconstructed metabolic networks to demonstrate the availablitity of Model Editor.
Once the reconstructed models imported into the Model Editor, users can start to add, refine and build their own models and run FBA as well in the Model Editor.
Because two kinds of data formats, spreadsheet and xml, are commonly used for metabolic reconstruction models, the Model Editor allows importing both formats.
Reconstruction Models (GPR)
Two layers of relations between "gene and protein" and "protein and reaction" can be summarized in a three-sheet spreadsheet.
Gene Index (A basic description of gene)
5'Coordinate, Locus Tag, Gene, Product, EC Number
Protein Index (Protein information and the association between protein and gene)
Abbreviation, Name, Gene
Reaction Index (Reaction information and the association between reaction and protein)
Abbreviation, Name, Equation, Protein, Subsystem
Available models: iAF1260 GPR.xls, iYL1228
Reconstruction Models Most published metabolic models, assembly of biochemical reactions, are available in either spreedsheet or SBML format. Available models in Excel: (Please note that the excel files provided here were modified according to Format of database.)
Bacillus subtilis, iYO844 (BiGG), original release, iYO844.xls Buchnera aphidicola, iGT196 (BiGG), original release, iGT196.xls Saccharomyces cerevisiae, iMM904 (BiGG), original release, iMM904.xls Salmonella typhimurium,iRR1083 (BiGG), original release, iRR1083.xls Shewanella oneidensis, iSO783 (BiGG), original Release, iSO783.xls Available models in SBML:
Models exported from BiGG can be modified by TextReplacer with the replacing rules (RulesforBiGG.TXT) and then imported to Model Editor. [2] Palsson B: Metabolic systems biology. FEBS Lett 2009, 583(24):3900-3904.
Model Name
Original
Modified
E. coli iAF1260
iAF1260.xml
Out iAF1260.xml
E. coli textbook
textbook.xml
Out textbook.xml
H. sapiens Recon 1
Recon1.xml
Out Recon1.xml
S. cerevisiae iND750
iND750.xml
Out iND750.xml
M. barkeri iAF692
iAF692.xml
Out iAF692.xml
H. pylori iIT341
iIT341.xml
Out iIT341.xml
S. aureus iSB619
iSB619.xml
Out iSB619.xml
M. tuberculosis iNJ661
iNJ661.xml
Out iNJ661.xml
Models downloaded from Model SEED can be modified by TextReplacer with the replacing rules (RulesforSEED.TXT) and then imported to Model Editor. Because the Model SEED provides more than one hundred of draft models, several of them were listed here as examples.
Model Name
Original
Modified
Acinetobacter sp. ADP1 ( Opt62977.3 )
Opt62977.3.xml
Out Opt62977.3.xml
Bacillus subtilis subsp. subtilis str. 168 ( Seed224308.1 )
Seed224308.1.xml
Out Seed224308.1.xml
Staphylococcus aureus subsp. aureus N315 ( Opt158879.1 )
Opt158879.1.xml
Out Opt158879.1.xml
In addition to the BiGG- and SEED-based models, several published models were made by using the resource of BioCyc and KEGG. These models can be modified and imported into the Model Editor. For example, the SBML file of Haloalkaliphile Natronomonas pharaonis original release can be modified by TextReplacer with the replacing rules (RulesforKEGG.TXT).
---- [1] Becker SA, Feist AM, Mo ML, Hannum G, Palsson BO, Herrgard MJ: Quantitative prediction of cellular metabolism with constraint-based models: the COBRA Toolbox. Nat Protoc 2007, 2(3):727-738.