Department for Computational Molecular Biology, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany. goeke@molgen.mpg.de|Department for Computational Molecular Biology, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany. goeke@molgen.mpg.de|Department for Computational Molecular Biology, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany. goeke@molgen.mpg.de|Department for Computational Molecular Biology, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany. goeke@molgen.mpg.de