A novel stabilization mechanism accommodating genome length variation in evolutionarily related viral capsids.

ABSTRACT: Tailed bacteriophages are one of the most numerous and diverse group of viruses. They store their genome at quasi-crystalline densities in capsids built from multiple copies of proteins adopting the HK97-fold. The high density of the genome exerts an internal pressure, requiring a maturation process that reinforces their capsids. However, it is unclear how capsid stabilization strategies have adapted to accommodate the evolution of larger genomes in this virus group. Here we characterized a novel capsid reinforcement mechanism in two evolutionary-related actinobacteriophages that modifies the length of a stabilization protein to accommodate a larger genome while maintaining the same capsid size. We used cryo-EM to reveal that capsids contained split hexamers of HK97-fold proteins with a st

SUBMITTER: Podgorski JM 

PROVIDER: S-EPMC10635136 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature