Congratulations to Dr. Ed Egelman and colleagues for a paper that will be featured on the cover of the April 14 issue of Cell.
For the last 65 years it has been understood that most viruses are either spherical (icosahedral) or rod-like (helical). However, many spindle-shaped (or lemon-shaped) viruses that infect archaea have been found, and these have appeared to be inconsistent with this paradigm. In this issue, Wang et al. show how the spindle shape is due to strands of hydrophobic subunits that can slide past each other, allowing quasi-equivalent interactions to be maintained. These quasi-equivalent interactions extend seamlessly into the helical tails that can emerge from the spindle-shaped body of the virions. Since the internal pressure of the genome causes a structure that would be rod-like to bulge, it suggests how such helical viruses evolved to become spindle-shaped to accommodate larger genomes. The cover shows an electron micrograph of negatively stained spindle-shaped virions that infect hyperthermophilic archaea. Image from Virginija Cvirkaite-Krupovic.
For the full article: