1. Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52074, Aachen, Germany
2. Univ Paris Est Creteil and Université Paris Cité, CNRS, LISA, F-94010, Créteil, France
3. Institut Universitaire de France (IUF), F-75231, Paris cedex 05, France
4. Department of Computer Science, VU Bioinformatics, Vrije Universiteit Amsterdam, De Boelelaan 1111, 1081 HV, Amsterdam, The Netherlands