INTRON AND RNA SPLICING IN ARCHAEA

抄録

  In Archaea, almost all introns in pre-tRNA, pre-rRNA, and pre-mRNA are spliced through two common steps by protein enzymes: cleavage of the precursor with splicing endonuclease, and ligation of the exons with RNA ligase. We found the first examples of archaeal pre-mRNA splicing and cleavage of the pre-mRNA with a novel subclass of archaeal splicing endonuclease. We further solved the novel tertiary structure of the splicing endonuclease, and revealed that the lineage-specific insertion of amino acid residues in the endonuclease expands the recognition of the substrate precursor RNA. We also discuss the possible involvement of tRNA splicing and its machinery in the origin of the tRNA molecule.