title: Convergent evolution of two different random RNAs for specific interaction with methionyl-tRNA synthetase.
abstract: Aminoacyl-tRNA synthetases (ARSs) recognize a specific sequence or structural characteristics of their cognate tRNAs. To contribute to the understanding how these recognition sites were selected, we generated two different RNA libraries containing either 42mer or 70mer random sequence and used them to select RNA aptamers that specifically bound to methionyl-tRNA synthetase (MRS) of Mycobacterium tuberculosis. The aptamer pools selected from the two RNA libraries showed strong binding affinity and selectivity to M. tuberculosis MRS compared to that of the homologous Escherichia coli MRS. The RNA aptamers selected from the two completely unrelated RNA pools shared the octamer sequence including CAU and the anticodon sequence of tRNA(Met). The secondary structure prediction suggested that the octamer motif in the selected aptamers would form a loop similar to the anticodon loop of tRNA(Met). The results suggest that the RNA loop containing CAU triplet could selected as a major recognition site for MRS during evolution more or less regarding, and also showed that species-specific ARS inhibitors can be obtained by in vitro evolution.
authors: Center for Medicinal Protein Network and Systems Biology, Seoul National University, Seoul 151-742, Republic of Korea.
authors: Taehee
authors: T
authors: Kang
authors: Gyuyoup
authors: G
authors: Kim
authors: Sang Gyu
authors: SG
authors: Park
authors: Young Joon
authors: YJ
authors: Jo
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D019020:Directed Molecular Evolution; D004926:Escherichia coli / Q000201:enzymology; D019143:Evolution, Molecular; D008718:Methionine-tRNA Ligase / Q000378:metabolism*; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000201:enzymology; D009690:Nucleic Acid Conformation; D012358:RNA, Transfer, Met / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: D052157:Aptamers, Nucleotide; D012358:RNA, Transfer, Met; D008718:Methionine-tRNA Ligase