Hebrew University of Jerusalem - Department of Microbiology and Molecular Genetics, Hebrew University of Jerusalem - Department of Microbiology and Molecular Genetics, Hebrew University of Jerusalem - Department of Microbiology and Molecular Genetics, Hebrew University of Jerusalem - Department of Microbiology and Molecular Genetics, Hebrew University of Jerusalem - Department of Microbiology and Molecular Genetics, Weizmann Institute of Science - Electron Microscopy Unit, Hebrew University of Jerusalem - Department of Biochemistry and Molecular Biology, Weizmann Institute of Science - Department of Molecular Genetics and Hebrew University of Jerusalem - Department of Microbiology and Molecular Genetics