The Pathway Tools Software in 2009

Pathway Tools is a production-quality software environment for creating a type of modelorganism database (MOD) called a Pathway/Genome Database (PGDB). A PGDB such as EcoCyc integrates the evolving understanding of the genes, proteins, metabolic network, and regulatory network of an organism. This article provides an overview of Pathway Tools capabilities. The software performs multiple computational inferences including prediction of metabolic pathways, prediction of metabolic pathway hole fillers, and prediction of operons. It enables interactive editing of PGDBs by database curators. It supports Web publishing of PGDBs, and provides a large number of query and visualization tools. The software also supports comparative analyses of PGDBs, and provides several systems biology analyses of PGDBs including reachability analysis of metabolic networks, and interactive tracing of metabolites through a metabolic network. More than 800 PGDBs have been created using Pathway Tools by scientists around the world, many of which are curated databases for important model organisms. Those PGDBs can be exchanged using a peer-to-peer database sharing system called the PGDB Registry.