1. Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
2. Institute of Biophysical Chemistry, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
3. Institute for Organic Chemistry and Chemical Biology, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
4. Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Universitat Pompeu Fabra (UPF), Institucio Catalana de Recerca i Estudis Avançats (ICREA), 08002 Barcelona, Spain