FIG. 8.

(A) RNA secondary-structure prediction of the LTH and flanking sequences of EAV strain Bucyrus and construct D5DcΔ1-184. The arrow signifies a possible switch between the two possible conformations of the EAV LTH region. Structure stability is indicated with a free-energy value. (B) RNA-secondary structure predictions of the LTH regions of different arteriviruses, with possibilities for the formation of an extended LTH stem in each of them. Depicted are LDV strain Plagemann, PRRSV strains VR-2332 and Lelystad, and simian hemorrhagic fever virus strain LVR 42-0/M6941. A box indicates base pair covariations between two PRRSV strains. The position where each predicted stem extension of the LTH starts is indicated with an arrowhead. The replicase translation initiation codon is shown in boldface italic font, and the leader TRS is indicated in boldface font.