3MMP image
Entry Detail
PDB ID:
3MMP
Keywords:
TRANSFERASE
Title:
Structure of the Qb replicase, an RNA-dependent RNA polymerase consisting of viral and host proteins
Biological Source:
Source Organism:
Escherichia coli, Enterobacteria phage Qbeta
Host Organism:
Escherichia coli
PDB Version:
Deposition Date:
2010-04-20
Release Date:
2010-06-09
Method Details:
Experimental Method:
X-RAY DIFFRACTION
Resolution:
2.50 Å
R-Value Free:
0.23
R-Value Work:
0.21
R-Value Observed:
0.21
Space Group:
C 1 2 1
3MMP validation report
Macromolecular Entities
Protein Blast
Polymer Type:polypeptide(L)
Description:Elongation factor Tu 2, Elongation factor Ts
Chain IDs:A, C
Chain Length:678
Number of Molecules:2
Biological Source:Escherichia coli
UniProt ID:P0A6P1 Pfam ID:PF00889
Protein Blast
Polymer Type:polypeptide(L)
Description:RNA-directed RNA polymerase beta chain
Chain IDs:B (auth: G), D (auth: F)
Chain Length:589
Number of Molecules:2
Biological Source:Enterobacteria phage Qbeta
UniProt ID:P14647 Pfam ID:PF03431
Ligand Molecules
PXN
Primary Citation
Structure of the Qbeta replicase, an RNA-dependent RNA polymerase consisting of viral and host proteins.
Proc.Natl.Acad.Sci.USA 107 10884 10889 (2010)
PMID: 20534494 DOI: 10.1073/pnas.1003015107

Abstact

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 evolution of resistance by the host appears to be impaired because of the interactions of the beta-subunit with parts of EF-Tu essential in recognition of aminoacyl-tRNA.

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Primary Citation of related structures
3MMP