Review Article
Archaea Signal Recognition Particle Shows the Way
Table 2
Taxonomic distribution of archaea SRP features. Indicated are the archaea subdomains, the number of species identified in each group, and a representative species. Features are the UGUNR motif (N is any nucleotide and R is a purine residue), helices (typically 1 to 4) in the small SRP domain (SD), the GNAR tetranucleotide loop (tetraloop) of helix 6, the GGAA tetraloop of helix 8, proteins SRP19 and SRP54 (SRP19/54), and the acidic (A) domain of the FtsY receptor (FtsY-A). “” shows presence, “” absence, and “” indicates that this feature is present only in a subset of the group members. Sequences deviating from the top-listed motif (e.g., the GGGA in the Thermoproteales) are given. The structural alignments of the 81 identified archaea SRP RNAs and the protein alignments of SRP19, SRP54 and FtsY are provided online as listed in Supplementary Materials 2 available online at doi:10.1155/2010/485051and are available at http://rnp.uthct.edu/rnp/SRPDB/srprna.html. Features of the SRP RNA in all three domains of life have been recently described in detail in [1].
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