We describe GOTax (http://gotax.bioinf.mpi-inf.mpg.de/), a 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. This way the distribution of
biological
processes and molecular activities can be analyzed over different taxonomic
groups. In particular, a measure of functional similarity, based on Gene
Ontology,
is available for comparing proteins and protein families, establishing
functional relationships
independent of evolution.