Isobase (IsoRank PPI Network Alignment Based Ortholog Database) is a database of functionally related orthologs, which we term "isologs", developed from the multiple alignment of five major eukaryotic PPI networks, as computed by the global network alignment tools IsoRank and IsoRankN - the "iso-" being motivated by the connection of our work to graph isomorphism. Isologs are proteins that perform functionally equivalent roles in different species. By emphasizing both sequence similarity and functional similarity, isologs are intended to address some of the shortcomings of traditional sequence-only orthology-prediction approaches.

How to use Isobase: You can browse through groups of orthologs common to two or more species, bulk-download all isologs across multiple species, and search for orthologs based on a constituent gene id/name or keyword. You can also execute multiple queries simultaneously by uploading a plain text file consisting of multiple gene ids/names/keywords. A detailed tutorial is available here.

UPDATES: Predictions as a result of combining both protein-protein and genetic interactions in the Isorank algorithm are now available! Gene-gene interactions for yeast, fly, worm, and human were considered. Just check "YES" under the option "Include genetic interactions in the interaction network alignment?" in both Browse and Ortholog Search pages.