Capsid structure and its stability at the late stages of bacteriophage SPP1 assembly.

ABSTRACT: The structure of the bacteriophage SPP1 capsid was determined at subnanometer resolution by cryo-electron microscopy and single-particle analysis. The icosahedral capsid is composed of the major capsid protein gp13 and the auxiliary protein gp12, which are organized in a T=7 lattice. DNA is arranged in layers with a distance of ~24.5 Å. gp12 forms spikes that are anchored at the center of gp13 hexamers. In a gp12-deficient mutant, the centers of hexamers are closed by loops of gp13 coming together to protect the SPP1 genome from the outside environment. The HK97-like fold was used to build a pseudoatomic model of gp13. Its structural organization remains unchanged upon tail binding and following DNA release. gp13 exhibits enhanced thermostability in the DNA-filled capsid. A remarkable conv

SUBMITTER: White HE 

PROVIDER: S-EPMC3393595 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature