Department of Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, 66123 Saarbruecken, Germany.|Department of Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, 66123 Saarbruecken, Germany.|Department of Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, 66123 Saarbruecken, Germany.