Heating-induced transition of Potyvirus Potato Virus A coat protein into β-structure

Abstract

In our previous communication, we have reported that virions of plant Potyvirus Potato Virus A (PVA) have a peculiar structure characterized by high content of disordered regions in intravirus coat protein (CP). In this report, we describe unusual properties of the PVA CP. With the help of a number of physicochemical methods, we have observed that the PVA CP just released from the virions by heating at 60–70 °C undergoes association into oligomers and transition to β- (and even cross-β-) conformation. Transition to β-structure on heating has been recently reported for a number of viral and non-viral proteins. The PVA CP isolated by LiCl method was also transformed into cross-β-structure on heating to 60 °C. Using the algorithms for protein aggregation prediction, we found that the aggregation-prone segments should be located in the central region of a PVA CP molecule. Possibly this transition mimics some functions of PVA CP in the virus life cycle in infected plants.

Keywords:

• Potato Virus A
• PVA coat protein
• heating-induced transition
• disordered and β-structures
• amyloid structures

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work has been supported by the project [AR11121 Estonia) and by the Russian Foundation for Basic Research Program [project no. 13-04-00290-a], [15-04-01406-a].