1. Department of Biological Chemistry; Weizmann Institute of Science; Rehovot Israel
2. Israel Structural Proteomics Center; Weizmann Institute of Science; Rehovot Israel
3. Migal-Galilee Research Institute; S. Industrial Zone Kiryat Shmona Israel
4. Department of Biochemistry and Molecular Biology and the Center for Advanced Biotechnology and Medicine; Robert Wood Johnson Medical School; Rutgers University; 679 Hoes Lane West Piscataway NJ 08854 USA