Auto-assembly and maturation of capsid proteins

in viral infectious cycle

  Viruses behave like nano-machines intended to transmit their genetic material (DNA or RNA) from a host cell to another. The proteins composing the capsid (external hull) of the viruses have particular properties of auto-assembly, especially interesting for their solidity and their resistance to extreme environmental conditions, and for their plasticity allowing the injection of the genetic materiel in the lately infected host cell.
Within the framework of this research topic, we study the structure and the plasticity of plant viruses such as the Tobacco Mosaic Virus, (TMV), Tomato Bushy Stunt Virus (TBSV)... by combined approaches of 3D cryoelectron microscopy, Small angle X-ray scattering (SAXS), and of molecular modeling (HCA and normal modes).

	Aramayo R, Mérigoux C, Larquet E, Bron P, Pérez JP, Dumas C, Vachette P and Boisset N. Divalent ion-dependent swelling of Tomato Bushy Stunt Virus: a multi-approach study. Biochim. Biophys. Acta 2005, 1724 : 345-54.

We study also certain viruses of archaebacteriae found in hot (+ 85°C ) and acid sources (pH 2) of volcanic origin. These particular viruses resist these extreme conditions and have the ability to reorganize their external envelope to grow proteinic tubes at the end of which "hooks" seem to promote contacts with new bacteria hosts. We study the structure and the temperature-dependent rehandling of the proteins forming these tubes.

	Prangishvili D, Vestergaard G, Haring M, Aramayo R, Basta T, Rachel R et Garrett RA. Structural and genomic properties of the hyperthermophilic archaeal virus ATV with an extracellular stage of the reproductive cycle J. Mol. Biol., 2006, 359(5), 1203-16.