GOTax: investigating biological processes and biochemical activities along the taxonomic tree

We describe GOTax (http://gotax.bioinf.mpi-inf.mpg.de/), a comparative genomics platform that integrates protein annotation with protein family classification and taxonomy. User-defined sets of proteins, protein families, annotation terms or taxonomic groups can be selected and compared, allowing for the analysis of distribution of biological processes and molecular activities over different taxonomic groups. In particular, a measure of functional similarity is available for comparing proteins and protein families, establishing functional relationships independent of evolution