The enzymology of a viral genome packaging motor is influenced by the assembly state of the motor subunits.

ABSTRACT: Terminase enzymes are responsible for the excision of a single genome from a concatemeric precursor (genome maturation) and concomitant packaging of DNA into the capsid shell. Here, we demonstrate that lambda terminase can be purified as a homogeneous "protomer" species, and we present a kinetic analysis of the genome maturation and packaging activities of the protomeric enzyme. The protomer assembles into a distinct maturation complex at the cos sequence of a concatemer. This complex rapidly nicks the duplex to form the mature left end of the viral genome, which is followed by procapsid binding, activation of the packaging ATPase, and translocation of the duplex into the capsid interior by the terminase motor complex. Genome packaging by the protomer shows high fidelity with only the matu

SUBMITTER: Andrews BT 

PROVIDER: S-EPMC3515665 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature