The sarcin/ricin motif is a highly conserved sequence found in the RNA of all large ribosomal subunits. The sarcin/ricin motif forms a crucial site for the binding of elongation factors EF-Tu and EF-G, but its precise functional role is unknown. The sarcin/ricin motifs are containing a GAGA tetraloop, a G-bulged, a flexible region and a terminal A-form duplex. Find RNA 3D (FR3D) is a suite of Matlab program that implement geometric, symbolic, or mixed search algorithms. Using this software we detected the sarcin/ricin motif in Haloarcula Marismortuiy and (3G4S, 3CXC, 3G6E) and analyzed the tertiary structures of in Thermus Thermophilus (2WDG) and 28S rRNA rat (1Q93). For this purpose, we illustrated symbolic search capabilities of FR3D for five, seven and nine nucleotides. Symbolic searches were conducted with guarantee cutoff and relaxed cutoff set to 0.5. G-bulged and flexible region of sarcin– ricin motif were identified in mentioned species. Certain relationships between bases were specified as follows: Query.Edges{1, 2}= tHS; Query.Edges{3, 5}= cHS; Query.Edges{3, 4}= tWH; Query.Edges{6,7} = tHH, Query.Edges{8, 9}= tHH.

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