Molecular structures of viruses from Raman optical activity.
A vibrational Raman optical activity (ROA) study of a range of different structural types of virus exemplified by filamentous bacteriophage fd, tobacco mosaic virus, satellite tobacco mosaic virus, bacteriophage MS2 and cowpea mosaic virus has revealed that, on account of its sensitivity to chirality, ROA is an incisive probe of their aqueous solution structures at the molecular level. Protein ROA bands are especially prominent from which, as we have shown by comparison with the ROA spectra of proteins with known structures and by using a pattern recognition program, the folds of the major coat protein subunits may be deduced. Information about amino acid side-chain conformations, exemplified here by the determination of the sign and magnitude of the torsion angle chi(2,1) for tryptophan in fd, may also sometimes be obtained. By subtracting the ROA spectrum of the empty protein capsid (top component) of cowpea mosaic virus from those of the intact middle and bottom-upper components separated by means of a caesium chloride density gradient, the ROA spectrum of the viral RNA was obtained, which revealed that the RNA takes up an A-type single-stranded helical conformation and that the RNA conformations in the middle and bottom-upper components are very similar. This information is not available from the X-ray crystal structure of cowpea mosaic virus since no nucleic acid is visible.
Blanch
Ewan W
EW
Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK1.
Hecht
Lutz
L
Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK1.
Syme
Christopher D
CD
Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK1.
Volpetti
Vito
V
Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, UK2.
Lomonossoff
George P
GP
Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, UK2.
Nielsen
Kurt
K
Department of Chemistry, DTU 207, Technical University of Denmark, DK-2800 Lyngby, Denmark3.
Barron
Laurence D
LD
Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK1.
D017104:Bacteriophage M13 / Q000737:chemistry*; D017798:Comovirus / Q000737:chemistry* / Q000235:genetics; D017909:Levivirus / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D012367:RNA, Viral / Q000032:analysis; D014027:Tobacco Mosaic Virus / Q000737:chemistry*; D019400:Tobacco mosaic satellite virus / Q000737:chemistry*; D014764:Viral Proteins / Q000032:analysis*
D012367:RNA, Viral; D014764:Viral Proteins