2PO4

X-ray crystal structure of polymerase domain of the bacteriophage N4 virion RNA polymerase

Summary for 2PO4

• Entry DOI: 10.2210/pdb2po4/pdb
• Descriptor: Virion RNA polymerase (2 entities in total)
• Functional Keywords: right hand shape, transferase
• Biological source: Enterobacteria phage N4
• Cellular location: Virion : Q859P9
• Total number of polymer chains: 1
• Total formula weight: 121559.70

Authors

Murakami, K.S.,Davydova, E.K.,Rothman-Denes, L.B. (deposition date: 2007-04-25, release date: 2008-04-01, Last modification date: 2024-02-21)

Primary citation

Murakami, K.S.,Davydova, E.K.,Rothman-Denes, L.B.
X-ray crystal structure of polymerase domain of the bacteriophage N4 virion RNA polymerase
Proc.Natl.Acad.Sci.USA, 15:5046-5051, 2008

PubMed Abstract: Coliphage N4 virion RNA polymerase (vRNAP), which is injected into the host upon infection, transcribes the phage early genes from promoters that have a 5-bp stem-3 nt loop hairpin structure. Here, we describe the 2.0-A resolution x-ray crystal structure of N4 mini-vRNAP, a member of the T7-like, single-unit RNAP family and the minimal component having all RNAP functions of the full-length vRNAP. The structure resembles a "fisted right hand" with Fingers, Palm and Thumb subdomains connected to an N-terminal domain. We established that the specificity loop extending from the Fingers along with W129 of the N-terminal domain play critical roles in hairpin-promoter recognition. A comparison with the structure of the T7 RNAP initiation complex reveals that the pathway of the DNA to the active site is blocked in the apo-form vRNAP, indicating that vRNAP must undergo a large-scale conformational change upon promoter DNA binding and explaining the highly restricted promoter specificity of vRNAP that is essential for phage early transcription.

PubMed: 18362338
DOI: 10.1073/pnas.0712325105

Experimental method

X-RAY DIFFRACTION (2 Å)