Visualization of protein-nucleic acid interactions in a virus. Refined structure of intact tobacco mosaic virus at 2.9 A resolution by X-ray fiber diffraction.
The structure of tobacco mosaic virus (TMV) has been determined by fiber diffraction methods at 2.9 A resolution, and refined by restrained least-squares to an R-factor of 0.096. Protein-nucleic acid interactions are clearly visible. The final model contains all of the non-hydrogen atoms of the RNA and the protein, 71 water molecules, and two calcium-binding sites. Viral disassembly is driven by electrostatic repulsions between the charges in two carboxyl-carboxylate pairs and a phosphate-carboxylate pair. The phosphate-carboxylate pair and at least one of the carboxyl-carboxylate pairs appear to be calcium-binding sites. Nucleotide specificity, enabling TMV to recognize its own RNA by a repeating pattern of guanine residues, is provided by two guanine-specific hydrogen bonds in one of the three base-binding sites.
Namba
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Department of Molecular Biology, Vanderbilt University, Nashville, TN 37235.
Pattanayek
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Stubbs
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D000596:Amino Acids; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008961:Models, Structural; D008968:Molecular Conformation; D012367:RNA, Viral / Q000235:genetics*; D014027:Tobacco Mosaic Virus / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*; D014867:Water; D014961:X-Ray Diffraction
D000596:Amino Acids; D012367:RNA, Viral; D014764:Viral Proteins; D014867:Water; D002118:Calcium