Structure of the double-stranded RNA-binding domain of the protein kinase PKR reveals the molecular basis of its dsRNA-mediated activation.
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Nanduri S, Carpick BW, Yang Y, Williams BR, Qin J
Structure of the double-stranded RNA-binding domain of the protein kinase PKR reveals the molecular basis of its dsRNA-mediated activation.
EMBO J. 1998 Sep 15;17(18):5458-65.
- PubMed ID
- 9736623 [ View in PubMed]
- Abstract
Protein kinase PKR is an interferon-induced enzyme that plays a key role in the control of viral infections and cellular homeostasis. Compared with other known kinases, PKR is activated by a distinct mechanism that involves double-stranded RNA (dsRNA) binding in its N-terminal region in an RNA sequence-independent fashion. We report here the solution structure of the 20 kDa dsRNA-binding domain (dsRBD) of human PKR, which provides the first three-dimensional insight into the mechanism of its dsRNA-mediated activation. The structure of dsRBD exhibits a dumb-bell shape comprising two tandem linked dsRNA-binding motifs (dsRBMs) both with an alpha-beta-beta-beta-alpha fold. The structure, combined with previous mutational and biochemical data, reveals a highly conserved RNA-binding site on each dsRBM and suggests a novel mode of protein-RNA recognition. The central linker is highly flexible, which may enable the two dsRBMs to wrap around the RNA duplex for cooperative and high-affinity binding, leading to the overall change of PKR conformation and its activation.