title: Isolation and crystallization of a chimeric Qβ replicase containing Thermus thermophilus EF-Ts.
abstract: Qβ replicase is a protein complex responsible for the replication of the genomic RNA of bacteriophage Qβ. In addition to the phage-encoded catalytic β subunit, it recruits three proteins from the host Escherichia coli cell: elongation factors EF-Tu and EF-Ts and ribosomal protein S1. We prepared a chimeric Qβ replicase in which the E. coli EF-Ts is replaced with EF-Ts from Thermus thermophilus. The chimeric protein is produced in E. coli cells during coexpression of the genes encoding the β subunit and thermophilic EF-Ts. The developed isolation procedure yields a substantially homogeneous preparation of the chimeric replicase. Unlike the wild-type enzyme, the S1-less chimeric replicase could be crystallized. This result facilitates studies on the structure of Qβ replicase and the mechanism of recognition of its templates that can replicate in vitro at a record rate.
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
authors.forename: N N
authors.initials: NN
authors.lastname: Vasiliev
authors.forename: L
authors.initials: L
authors.lastname: Jenner
authors.forename: M M
authors.initials: MM
authors.lastname: Yusupov
authors.forename: A B
authors.initials: AB
authors.lastname: Chetverin
mesh_terms: D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000737:chemistry*; D021122:Protein Subunits / Q000737:chemistry; D011777:Q beta Replicase / Q000737:chemistry* / Q000302:isolation & purification; D016963:Thermus thermophilus / Q000235:genetics / Q000378:metabolism*
chemical_list: D010445:Peptide Elongation Factors; D021122:Protein Subunits; C023512:elongation factor Ts; D011777:Q beta Replicase