The primary structure of papaya mosaic virus coat protein

The amino acid sequence of the coat protein of the potexvirus papaya mosaic virus (PMV) has been determined, using a combination of the Edman degradation procedure (manual and automated) and mass spectrometry. The amino acid sequence is compared with that of the coat protein of potato virus X (PVX) as reported (S. Yu. Morozov, V. M. Zakhariev, B. K. Chernov, V. S. Prasolov, Yu. V. Kozlov, J. G. Atabekov, and K. G. Skyabin, Dokl. Acad. Nauk, SSSR 271, 211–215,1983). PMV has 73 of 211 amino acid residues in common with PVX and has 25 fewer residues in the polypeptide chain. Also 10 of a possible 16 proline residues are in similar positions in both proteins, including a sequence of 3 prolines at the carboxyl end. Furthermore, the 2 cysteine residues in PMV correspond with 2 of the 3 cysteines in PVX.