1. Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia
2. Pirogov Russian National Research Medical University, Ostrovitianov 1, 117997 Moscow, Russia
3. European Molecular Biology Laboratory, 69117 Heidelberg, Germany
4. Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States