Comparison of putative Yfr1 RNAs from 15 different Prochlorococcus and Synechococcus. A. Sequence alignment of the top scoring sequences obtained by BlastN using the known Yfr1 sequences  as a query. The respective strain numbers are prefixed "Pro" and "Syn" for Prochlorococcus and Synechococcus. B. Sequence/structure model for putative Yfr1 RNAs from 15 different Prochlorococcus and Synechococcus as shown in part A. Sequence is given in IUPAC-notation (R: A or G; Y: C or U; S: G or C; K: G or U; B: G, U or C; V: G, C or A; D: G, U or A; H: A, C or U). Base pair colors indicate the number of different base pairs which occur in the different sequences at this position (red = 1, yellow = 2, green = 3) and their shading resembles the frequency of base pairing, i.e. the number of sequences where this base pair is not present.