1. Gilead Sciences and IOCB Research Center, Institute of Organic Chemistry and Biochemistry of the Academy of Sciences of the Czech Republic, Prague, Czech Republic
2. Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
3. Gilead Sciences, Foster City, California, USA
4. Department of Medical Microbiology, Virology, University Medical Center Utrecht, Utrecht, The Netherlands
5. Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic, Prague, Czech Republic