Fig. 4.

(A) Schematic diagram of L-A cap-snatching mechanism. In the middle virion, m⁷Gp-His154 adduct is depicted by the asterisk. It is not known which Gag protein in the virion participates in the cap transfer reaction. mRNA decapping and cap transfer may be coupled with transcription (see text). (B) Comparison of selected L-A Gag sequences with those of other fungal totiviruses. His154 and crucial residues for cap recognition are indicated by the arrows. GenBank accession numbers are L-A (AAA50320.1), TaV1 (ADQ54105.1), BRVF (YP 001497150.1), and L-BC (NP 042580.1).