FIG. 1.

(A) DNA and deduced protein sequences of the A2 genome region surrounding the 3′ end of orf5; in the DNA, the slippery sequence is indicated in italics and bold, the loop is indicated by converging arrows, and the segments cloned in the −1 frame under the lacZ promoter of pUC18 are underlined, with their ends represented by a diamond and a dot. The underlined polypeptides correspond to those obtained by MALDI-TOF as part of gp5A and gp5B (the first of them) or as part of gp5B alone (the other two). (B) Proposed secondary structure of the mRNA frameshift-stimulatory element located downstream from the slippery sequence.