[1] Max Planck Res Unit Enzymol Prot Folding, D-01620 Halle, Saale, Germany
[2] Univ Halle Wittenberg, D-01620 Halle, Saale, Germany
[3] Brandeis Univ, Rosenstiel Basic Med Sci Res Ctr, Waltham, MA 02454 USA
[4] Brandeis Univ, Howard Hughes Med Inst, Waltham, MA 02454 USA