Assignation of PaMx73 virion proteins by mass spectrometry analysis. The protein components of PaMx73 purified virions were resolved by SDS-PAGE and stained with Coomassie brilliant blue. A molecular weight marker was included for reference in the left lane. The virion proteins were assigned by mass spectrometry to the corresponding ORFs (see Methods). All core ORFs are numbered as in Figure 4. ORF h was the only accessory ORF that was part of the virion. After the ORF numbers, in parenthesis, appears the percentage of amino acid sequence coverage obtained in the assay and the theoretical molecular weight of the identified protein.