Fig. 1. Architecture of the SRP Alu domain.

a Schematic showing the composition of the eukaryotic SRP bound to the ribosome-nascent chain complex (RNC). b Schematic representation of SRP Alu RNA from the three domains of life: Bacteria, archaea, and eukarya. SRP9/14 proteins are shown for organisms where they have been annotated. A dashed line indicates the border between the Alu and S domains. The conserved UGU motif is colored in blue. c Construct for the entire PfAlu RNA (PfAlu118) where the S domain is replaced by a GUAA tetraloop (gray). Base-pair information is depicted as previously predicted⁸. Nucleotides mutated due to the hammerhead ribozyme and T7 RNA polymerase production requirements are highlighted in red.