Biochemical analysis of the capsid protein gene and capsid protein of tobacco etch virus: N-terminal amino acids are located on the virion's surface.

The sequence of the 1491 nucleotides found at the 3' end of the genome of the highly aphid-transmissible (HAT) isolate of tobacco etch virus (TEV) has been determined. The nucleotide sequence of the capsid protein gene has been identified and compared with the corresponding region of the not-aphid-transmissible (NAT) isolate of TEV and with pepper mottle virus (PeMV). The deduced amino acid sequences of the two TEV capsid proteins displayed 98% homology and a 66% homology with PeMV capsid protein. Three of the six amino acid differences between the capsid proteins of the two TEV isolates occurred near the N terminus of the protein. Biochemical and immunological evidence suggested the N-terminal 29 amino acids of the capsid protein were hydrophilic and were located at or near the virion's surface.