Molecular and Computational Biology Section, Division of Biological Sciences, University of Southern California, Los Angeles, California, USA. andrewds@usc.edu.|Molecular and Computational Biology Section, Division of Biological Sciences, University of Southern California, Los Angeles, California, USA. andrewds@usc.edu.|Molecular and Computational Biology Section, Division of Biological Sciences, University of Southern California, Los Angeles, California, USA. andrewds@usc.edu.|Faculty of Computer and Information Science, University of Ljubljana, Trzaska 25, SI 1000 Ljubljana, SI, Slovenia. uros.lotric@fri.uni-lj.si.