This lecture explores the interaction between hsp70 and the intrinsically disordered Ntail domain of the measles virus nucleoprotein. It delves into the pivotal role of the P protein in transcription and replication, the characteristics of intrinsically disordered proteins, and the a-helical folding of the MeV NTAIL upon binding to the X domain of P. The lecture also covers the molecular partnership of NTAIL, the impact of hsp70 on viral proteins, and the modulation of hsp70-substrate interactions. Furthermore, it discusses the split-GFP re-assembly assay principle, the rational design of mutated MORE variants, and the implications of phase transition and fibril formation in viral proteins.