Figure 2.

RyfA1 and RyfA2 structure and sequence. (a) The predicted genes ryfA1 and ryfA2 were aligned using Clone Manager version 9. The genes encoding the sibling RyfA molecules are 95% identical in S. dysenteriae. Nucleotide differences between ryfA1 and ryfA2 are highlighted with light gray rectangles and the identified five nucleotide “variable region” of each is boxed in black. (b) The mfold Web Server [22] was used to predict the structures of RyfA1 and RyfA2. Although the predicted structure between each sibling RyfA is nearly identical, the stem loops outlined in the black boxes vary between the two molecules. The observed structural differences between RyfA1 and RyfA2 result from the varied nucleic acid sequences within the five nucleotide variable region (as indicated by the gray boxes) identified upon a comparison of each ryfA gene.