[1] CEA, Lab Struct Prot, Dept Ingn & Etud Prot, F-91191 Gif Sur Yvette, France
[2] Univ Minnesota, Hormel Inst, Austin, MN 55912 USA
[3] Umea Univ, Dept Med Biosci Med Genet, S-90185 Umea, Sweden
[4] Burnham Inst, La Jolla, CA 92037 USA
[5] Umea Univ, Dept Immunol, S-90185 Umea, Sweden