Portal-large terminase interactions of the bacteriophage T4 DNA packaging machine implicate a molecular lever mechanism for coupling ATPase to DNA translocation.

ABSTRACT: DNA packaging by double-stranded DNA bacteriophages and herpesviruses is driven by a powerful molecular machine assembled at the portal vertex of the empty prohead. The phage T4 packaging machine consists of three components: dodecameric portal (gp20), pentameric large terminase motor (gp17), and 11- or 12-meric small terminase (gp16). These components dynamically interact and orchestrate a complex series of reactions to produce a DNA-filled head containing one viral genome per head. Here, we analyzed the interactions between the portal and motor proteins using a direct binding assay, mutagenesis, and structural analyses. Our results show that a portal binding site is located in the ATP hydrolysis-controlling subdomain II of gp17. Mutations at key residues of this site lead to temperature-

SUBMITTER: Hegde S 

PROVIDER: S-EPMC3318623 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature