Bioinformatics center, Institute of Molecular Biology and Physiology, University of Copenhagen, Universitetsparken 15, Building 10, DK-2100 Copenhagen, Denmark. wb@binf.ku.dk|Bioinformatics center, Institute of Molecular Biology and Physiology, University of Copenhagen, Universitetsparken 15, Building 10, DK-2100 Copenhagen, Denmark. wb@binf.ku.dk