1. Department of Biochemistry and Molecular BiophysicsColumbia UniversityNew York NY10032
2. Howard Hughes Medical Institute, Columbia UniversityNew York NY10032
3. Department of Cell BiochemistryUniversity of GroningenNijenborgh 7Groningen9747 AG Netherlands
4. Structural Biology BrusselsVrije Universiteit BrusselPleinlaan 2Brussel1050 Belgium
5. Structural Biology Research CenterVIB, Pleinlaan 2Brussel1050 Belgium