Mapping α‐helical induced folding within the intrinsically disordered C‐terminal domain of the measles virus nucleoprotein by site‐directed spin‐labeling EPR spectroscopy

• DOI: 10.1002/prot.22125
• Publication Date: 2008-06-05T17:21:16Z
• Authors: Valérie Belle; Sabrina Rouger; Stéphanie Costanzo; Elodie Liquière; Janez Strancar; Bruno Guigliarelli; André Fournel; Sonia Longhi
• Keywords: Nucleoprotein; Site-directed spin labeling; Folding (DSP implementation)

Abstract Using site‐directed spin‐labeling EPR spectroscopy, we mapped the region of intrinsically disordered C‐terminal domain measles virus nucleoprotein (N TAIL ) that undergoes induced folding. In addition to four spin‐labeled N variants (S407C, S488C, L496C, and V517C) (Morin et al. (2006), J Phys Chem 110: 20596‐20608), 10 new single‐site cysteine were designed, purified from E. coli, spin‐labeled. These 14 enabled us map in detail gain rigidity presence either secondary structure stabilizer 2,2,2‐trifluoroethanol or X (XD) viral phosphoprotein. Different regions shown contribute a different extent binding XD, while mobility spin labels grafted at positions 407 460 was unaffected upon XD; within 488–502 505–522 severely moderately reduced, respectively. Furthermore, experiments 30% sucrose allowed precisely residues 488–502, undergoing α‐helical The found be restrained even absence partner, behavior could accounted for by existence transiently populated folded state. Finally, show motion XD is due transition occurring not direct interaction with XD. Proteins 2008. © 2008 Wiley‐Liss, Inc.