1. Institute for Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany
2. Bioinformatics Group, Department of Computer Science and Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstr. 16–18, 04107 Leipzig, Germany
3. Max Planck Institute for Mathematics in the Science, Inselstr. 22, 04103 Leipzig, Germany
4. Institute for Theoretical Chemistry, University of Vienna, Währingerstr. 17, A-1090 Vienna, Austria
5. Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA