Secondary structures of narcissus mosaic virus coat protein

¹ Department of Biological and Molecular Sciences, University of Stirling, Stirling FK9 4LA, U.K.
² Department of Applied Physics and Electronic and Manufacturing Engineering, University of Dundee, Dundee DD1 4HN, U.K.
³ Department of Biochemistry, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, U.K.
and⁴ Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, U.K.

Circular dichroism (CD) measurements on the coat protein of narcissus mosaic virus particles show that the dominant secondary structure is the α-helix, with a 45 (±2)% content. The -sheet content is much lower at 5 (±3)%. Both values are essentially the same as those found in potato virus X coat protein. The CD results are used to assess the results of secondary structure prediction methods.