Structure of the Qbeta replicase, an RNA-dependent RNA polymerase consisting of viral and host proteins.

ABSTRACT: The RNA-dependent RNA polymerase core complex formed upon infection of Escherichia coli by the bacteriophage Qbeta is composed of the viral catalytic beta-subunit as well as the host translation elongation factors EF-Tu and EF-Ts, which are required for initiation of RNA replication. We have determined the crystal structure of the complex between the beta-subunit and the two host proteins to 2.5-A resolution. Whereas the basic catalytic machinery in the viral subunit appears similar to other RNA-dependent RNA polymerases, a unique C-terminal region of the beta-subunit engages in extensive interactions with EF-Tu and may contribute to the separation of the transient duplex formed between the template and the nascent product to allow exponential amplification of the phage genome. The evoluti

SUBMITTER: Kidmose RT 

PROVIDER: S-EPMC2890729 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature