2po4
X-ray crystal structure of polymerase domain of the bacteriophage N4 virion RNA polymerase
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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 | ||||||
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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