tRNA-like recognition of group I introns by a tyrosyl-tRNA synthetase.
The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) functions in splicing group I introns by promoting the formation of the catalytically active RNA structure. Previous work suggested that CYT-18 recognizes a conserved tRNA-like structure of the group I intron catalytic core. Here, directed hydroxyl-radical cleavage assays show that the nucleotide-binding fold and C-terminal domains of CYT-18 interact with the expected group I intron cognates of the aminoacyl-acceptor stem and D-anticodon arms, respectively. Further, three-dimensional graphic modeling, supported by biochemical data, shows that conserved regions of group I introns can be superimposed over interacting regions of the tRNA in a Thermus thermophilus TyrRS/tRNA(Tyr) cocrystal structure. Our results support the hypothesis that CYT-18 and other aminoacyl-tRNA synthetases interact with group I introns by recognizing conserved tRNA-like structural features of the intron RNAs.
Myers
Christopher A
CA
Institute for Cellular and Molecular Biology, Department of Chemistry and Biochemistry, and Section of Molecular Genetics and Microbiology, School of Biological Sciences, University of Texas, Austin, TX 78712, USA.
Kuhla
Birte
B
Cusack
Stephen
S
Lambowitz
Alan M
AM
D003001:Cloning, Molecular; D003545:Cysteine; D017665:Hydroxyl Radical; D007438:Introns; D008958:Models, Molecular; D009492:Neurospora crassa / Q000201:enzymology / Q000235:genetics; D009690:Nucleic Acid Conformation; D020836:Protein Structure, Quaternary; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D014448:Tyrosine-tRNA Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D017665:Hydroxyl Radical; D012343:RNA, Transfer; D014448:Tyrosine-tRNA Ligase; D003545:Cysteine