2po4
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| , resolution 2.000Å | |||||||
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| Gene: | gp50 (Enterobacteria phage N4) | ||||||
| Activity: | DNA-directed RNA polymerase, with EC number 2.7.7.6 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
X-ray crystal structure of polymerase domain of the bacteriophage N4 virion RNA polymerase
OverviewOverview
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.
About this StructureAbout this Structure
2PO4 is a Single protein structure of sequence from Enterobacteria phage n4. Full crystallographic information is available from OCA.
ReferenceReference
X-ray crystal structure of the polymerase domain of the bacteriophage N4 virion RNA polymerase., Murakami KS, Davydova EK, Rothman-Denes LB, Proc Natl Acad Sci U S A. 2008 Mar 24;. PMID:18362338
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