1. Department of Biological Chemistry; The Weizmann Institute of Science; Rehovot; 76100; Israel
2. Chemical Research Support; The Weizmann Institute of Science; Rehovot; 76100; Israel
3. Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Hadassah Medical School; The Hebrew University of Jerusalem; Jerusalem; 91120; Israel
4. Department of Molecular Microbiology and Biotechnology; Tel Aviv University; Ramat Aviv; 69978; Israel