TRNA-intron endonuclease

rdf:langString TRNA-intron endonuclease

rdf:langString tRNA-intron lyase

rdf:langString tRNA-intron lyase

rdf:langString tRNA-intron lyase (EC 4.6.1.16, tRNA intron endonuclease, transfer ribonucleate intron endoribonuclease, tRNA splicing endonuclease, splicing endonuclease, tRNATRPintron endonuclease, transfer splicing endonuclease; systematic name pretRNA lyase (intron-removing; cyclic-2′,3′-phosphate-forming)) is an enzyme. As an endonuclease enzyme, tRNA-intron lyase is responsible for splicing phosphodiester bonds within non-coding ribonucleic acid chains. These non-coding RNA molecules form tRNA molecules after being processed, and this is dependent on tRNA-intron lyase to splice the pretRNA. tRNA processing is an important post-transcriptional modification necessary for tRNA maturation because it locates and removes introns in the pretRNA. This enzyme catalyses the following chemical reaction: pretRNA = a 3′-half-tRNA molecule with a 5′-OH end + a 5′-half-tRNA molecule with a 2′,3′-cyclic phosphate end + an intron with a 2′,3′-cyclic phosphate and a 5′-hydroxyl terminus This enzyme catalyses one of the beginning stages in the maturation of tRNA molecules. Organisms from every group of the three-domain system relies on tRNA genes. Bacteria does not necessitate cleavage enzymes due to their ability to self-splice. Eukaryotic tRNA-intron endonucleases are hypothesized to evolve from archaeal tRNA-intron endonucleases. Various structures of tRNA-intron lyase have been identified in archaea, less is known about eukaryotic tRNA-intron lyase. The structure of tRNA-intron lyase are maintained by interactions of β strands of local subunits and an electrostatic interaction between a loop and pocket on nearby subunits. Active sites of tRNA-intron lyase are composed of tyrosine, histidine and lysine. Eukaryotes and archaea function similarly and follow the same mechanism to locate unwanted introns and carry out intron splicing. Splicing on both the 3' and 5' ends of the intron. tRNA-intron lyase requires a level of specificity to the splice site on the pre tRNA. Having a mutation to the splice site on the pre-tRNA could inhibit the enzyme from functioning at the appropriate sites. Although regulating molecules have been defined, current knowledge of understanding of exact mechanisms is limited. In mammals, including humans, mutations to the tRNA-intron lyase gene are associated with neurodegenerative diseases such as Pontocerebellar Hypoplasias (PCH). This disease leads to atrophy of the cerebellum and pons. This causes microcephaly, severe motor impairment, and severe mental impairment.