Figure 2.

Structure-based alignment of loop L1.2 and L2 sequences in SRP RNAs of animal metazoans, of plants and of eubacterial and archaeal species. (A) Nucleotides proposed to base pair are shown in red, sheared G-G pairs in blue and U-turns in green. First nucleotides in stems are shown in italic. Black bars delineate the loop sequences. For each species, only one representative is shown. Sequences were obtained from SRPDB. (B) Helix diagrams of mammalian, plant and archaeal Alu RNA 5′ domains. Asterisks highlight a conserved nucleotide in the archaeal RNAs. The helix diagram of a eubacterial SRP RNA resembles most closely the one of archaeal SRP RNAs.