Minihelix-loop RNAs: minimal structures for aminoacylation catalysts.
We report here an in vitro selected ribozyme, KL17, which is active in charging amino acids on its own 5'-OH group. The ribozyme consists of two catalytic domains, one of which (consisting of P5/P6/L6) recognizes amino acid substrates based on the steric environment of the side chain, whereas the other recognizes an aminoacylated oligonucleotide. The secondary structure of this ambidextrous ribozyme arranges into a pseudoknot, where L6 docks onto the 3'-terminal single-stranded region. The formation of this pseudoknot structure brings the P6 region, in which the essential catalytic core is most likely embedded, into the proximity of the 5'-OH group. Our studies show that the P6-L6 domain can be separated from the main body of KL17 and the derived P6-L6 minihelix-loop RNA can act as a trans-aminoacylation catalyst. In this report, we also compare this ribozyme with an analogous aminoacylation system previously characterized in our laboratory and illuminate the similarities and differences between these catalytic systems.
Ramaswamy
Krishna
K
Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, NY 14260-3000, USA.
Wei
Kenneth
K
Suga
Hiroaki
H
D000215:Acylation; D000596:Amino Acids / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D001483:Base Sequence; D020134:Catalytic Domain / Q000235:genetics; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016337:RNA, Catalytic / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017384:Sequence Deletion; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity
D000596:Amino Acids; D016337:RNA, Catalytic; D012313:RNA; D000604:Amino Acyl-tRNA Synthetases; D007930:Leucine