4Q7J

Complex structure of viral RNA polymerase

Summary for 4Q7J

• Entry DOI: 10.2210/pdb4q7j/pdb
• Related: 3AGP 3AGQ
• Descriptor: Elongation factor Ts, Elongation factor Tu 1, Q beta replicase, ... (6 entities in total)
• Functional Keywords: rna polymerase, rna binding motif, rna dependent rna polymerization, translation-transferase complex, translation/transferase
• Biological source: Escherichia coli; More
• Cellular location: Cytoplasm: P0A6P1 P0CE47
• Total number of polymer chains: 8
• Total formula weight: 342759.55

Authors

Takeshita, D. (deposition date: 2014-04-25, release date: 2014-08-27, Last modification date: 2023-11-08)

Primary citation

Takeshita, D.,Yamashita, S.,Tomita, K.
Molecular insights into replication initiation by Q beta replicase using ribosomal protein S1.
Nucleic Acids Res., 42:10809-10822, 2014

PubMed Abstract: Ribosomal protein S1, consisting of six contiguous OB-folds, is the largest ribosomal protein and is essential for translation initiation in Escherichia coli. S1 is also one of the three essential host-derived subunits of Qβ replicase, together with EF-Tu and EF-Ts, for Qβ RNA replication in E. coli. We analyzed the crystal structure of Qβ replicase, consisting of the virus-encoded RNA-dependent RNA polymerase (β-subunit), EF-Tu, EF-Ts and the N-terminal half of S1, which is capable of initiating Qβ RNA replication. Structural and biochemical studies revealed that the two N-terminal OB-folds of S1 anchor S1 onto the β-subunit, and the third OB-fold is mobile and protrudes beyond the surface of the β-subunit. The third OB-fold mainly interacts with a specific RNA fragment derived from the internal region of Qβ RNA, and its RNA-binding ability is required for replication initiation of Qβ RNA. Thus, the third mobile OB-fold of S1, which is spatially anchored near the surface of the β-subunit, primarily recruits the Qβ RNA toward the β-subunit, leading to the specific and efficient replication initiation of Qβ RNA, and S1 functions as a replication initiation factor, beyond its established function in protein synthesis.

PubMed: 25122749
DOI: 10.1093/nar/gku745

Experimental method

X-RAY DIFFRACTION (2.9 Å)