title: METANNOGEN: compiling features of biochemical reactions needed for the reconstruction of metabolic networks.
abstract: BACKGROUND
  One central goal of computational systems biology is the mathematical modelling of complex metabolic reaction networks. The first and most time-consuming step in the development of such models consists in the stoichiometric reconstruction of the network, i. e. compilation of all metabolites, reactions and transport processes relevant to the considered network and their assignment to the various cellular compartments. Therefore an information system is required to collect and manage data from different databases and scientific literature in order to generate a metabolic network of biochemical reactions that can be subjected to further computational analyses.
  
  
  RESULTS
  The computer program METANNOGEN facilitates the reconstruction of metabolic networks. It uses the well-known database of biochemical reactions KEGG of biochemical reactions as primary information source from which biochemical reactions relevant to the considered network can be selected, edited and stored in a separate, user-defined database. Reactions not contained in KEGG can be entered manually into the system. To aid the decision whether or not a reaction selected from KEGG belongs to the considered network METANNOGEN contains information of SWISSPROT and ENSEMBL and provides Web links to a number of important information sources like METACYC, BRENDA, NIST, and REACTOME. If a reaction is reported to occur in more than one cellular compartment, a corresponding number of reactions is generated each referring to one specific compartment. Transport processes of metabolites are entered like chemical reactions where reactants and products have different compartment attributes. The list of compartmentalized biochemical reactions and membrane transport processes compiled by means of METANNOGEN can be exported as an SBML file for further computational analysis. METANNOGEN is highly customizable with respect to the content of the SBML output file, additional data-fields, the graphical input form, highlighting of project specific search terms and dynamically generated Web-links.
  
  
  CONCLUSIONS
  METANNOGEN is a flexible tool to manage information for the design of metabolic networks. The program requires Java Runtime Environment 1.4 or higher and about 100 MB of free RAM and about 200 MB of free HD space. It does not require installation and can be directly Java-webstarted from http://3d-alignment.eu/metannogen/.
authors.affiliation: Institute of Biochemistry Charité, Medical Faculty of the Humboldt University, Berlin, Germany. christoph.gille@charite.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Gille
authors.forename: Sabrina
authors.initials: S
authors.lastname: Hoffmann
authors.forename: Hermann-Georg
authors.initials: HG
authors.lastname: Holzhütter
mesh_terms: D001669:Biochemical Phenomena; D001671:Biochemistry; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D006801:Humans; D020407:Internet; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D039781:PubMed; D012984:Software; D049490:Systems Biology