Coat protein of potyviruses. 2. Amino acid sequence of the coat protein of potato virus Y.

The amino acid sequence of the coat protein of potato virus Y (PVY), the type member of the potyvirus group, has been determined by protein sequencing techniques. The protein contains 267 amino acid residues with a calculated mol wt of 29,945. A comparison of the PVY coat protein sequence with those of tobacco etch virus (TEV) and pepper mottle virus (PeMV) predicted from nucleotide sequence data (R. F. Allison, J. G. Sorenson, M. E. Kelly, F. B. Armstrong, and W. G. Dougherty, Proc. Natl. Acad. Sci. USA82, 3969-3972, 1985; W. G. Dougherty, R. F. Allison, T. D. Parks, R. E. Johnston, M. J. Feild, and F. B. Armstrong, Virology 146,282-291, 1985) shows that sequence homology between the coat proteins from PVY and PeMV is 92% and that between PVY and TEV is 62%. These data suggest that PVY and PeMV are much more closely related than previously believed from serological studies.