Tertiary structure base pairs between D- and TpsiC-loops of Escherichia coli tRNA(Leu) play important roles in both aminoacylation and editing.
To ensure the fidelity of protein biosynthesis, aminoacyl-tRNA synthetases (aaRSs) must recognize the tRNA identity elements of their cognate tRNAs and discriminate their cognate amino acids from structurally similar ones through a proofreading (editing) reaction. For a better understanding of these processes, we investigated the role of tRNA(Leu) tertiary structure in the aminoacylation and editing reactions catalyzed by leucyl-tRNA synthetase (LeuRS). We constructed a series of Escherichia coli tRNA(Leu) mutated transcripts with alterations of the nucleotides involved in tertiary interactions. Our results revealed that any disturbance of the tertiary interaction between the tRNA(Leu) D- and TpsiC-loops affected both its aminoacylation ability and its ability to stimulate the editing reaction. Moreover, we found that the various tertiary interactions between the D- and TpsiC-loops (G18:U55, G19:C56 and U54:A58) functioned differently within the aminoacylation and editing reactions. In these two reactions, the role of base pair 19:56 was closely correlated and dependent on the hydrogen bond number. In contrast, U54:A58 was more important in aminoacylation than in editing. Taken together, our results suggest that the elbow region of tRNA formed by the tertiary interactions between the D- and TpsiC-loops affects the interactions between tRNA and aaRS effectively both in aminoacylation and in editing.
Du
Xing
X
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, The Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
Wang
En-Duo
ED
D000215:Acylation; D000255:Adenosine Triphosphate / Q000378:metabolism; D020029:Base Pairing; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics*; D006860:Hydrogen Bonding; D007532:Isoleucine / Q000378:metabolism; D007930:Leucine / Q000378:metabolism; D007935:Leucine-tRNA Ligase / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012356:RNA, Transfer, Leu / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D012329:RNA, Bacterial; D012356:RNA, Transfer, Leu; D007532:Isoleucine; D000255:Adenosine Triphosphate; D007935:Leucine-tRNA Ligase; D007930:Leucine