Related Experiment Video
Updated: Sep 12, 2026

Averaging of Viral Envelope Glycoprotein Spikes from Electron Cryotomography Reconstructions using Jsubtomo
Published on: October 21, 2014
Membrane proteins organize a symmetrical virus
K Forsell1, L Xing, T Kozlovska
1Karolinska Institute, Department of Biosciences at Novum, S-141 57 Huddinge, Sweden.
Abstract:
Alphaviruses are enveloped icosahedral viruses that mature by budding at the plasma membrane. According to a prevailing model maturation is driven by binding of membrane protein spikes to a preformed nucleocapsid (NC). The T = 4 geometry of the membrane is thought to be imposed by the NC through one-to-one interactions between spike protomers and capsid proteins (CPs). This model is challenged here by a Semliki Forest virus capsid gene mutant. Its CPs cannot assemble into NCs, or its intermediate structures, due to defective CP-CP interactions. Nevertheless, it can use its horizontal spike-spike interactions on membrane surface and vertical spike-CP interactions to make a particle with correct geometry and protein stoichiometry. Thus, our results highlight the direct role of membrane proteins in organizing the icosahedral conformation of alphaviruses.
Related Concept Videos
Viral Structure
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Fluid Mosaic Model
Intracellular Movement of Viruses and Bacteria
SNAREs and Membrane Fusion
SNAREs exist in pairs that symmetrically interact and catalyze the fusion of the lipid bilayers in vesicle and target organelle. v-SNARE in the vesicle membrane are single polypeptide chains that bind to a complementary t-SNARE, composed of 2...
Introduction to Virus

