Department of Computer Science, Informatics Institute, Christopher S, Bond Life Science Center, University of Missouri, Columbia, MO 65211, USA. chengji@missouri.edu.|Department of Computer Science, Informatics Institute, Christopher S, Bond Life Science Center, University of Missouri, Columbia, MO 65211, USA. chengji@missouri.edu.|Genetics & Experimental Bioinformatics, Institute for Biology 3, Faculty of Biology, Albert-Ludwigs-University Freiburg, Schänzlestr, 1, 79104 Freiburg, Germany. bjoern.voss@biologie.uni-freiburg.de.