8iss
From Proteopedia
Cryo-EM structure of wild-type human tRNA Splicing Endonuclease Complex bound to pre-tRNA-ARG at 3.19 A resolution
Structural highlights
FunctionSEN15_HUMAN Non-catalytic subunit of the tRNA-splicing endonuclease complex, a complex responsible for identification and cleavage of the splice sites in pre-tRNA. It cleaves pre-tRNA at the 5' and 3' splice sites to release the intron. The products are an intron and two tRNA half-molecules bearing 2',3' cyclic phosphate and 5'-OH termini. There are no conserved sequences at the splice sites, but the intron is invariably located at the same site in the gene, placing the splice sites an invariant distance from the constant structural features of the tRNA body. The tRNA splicing endonuclease is also involved in mRNA processing via its association with pre-mRNA 3' end processing factors, establishing a link between pre-tRNA splicing and pre-mRNA 3' end formation, suggesting that the endonuclease subunits function in multiple RNA-processing events.[1] Publication Abstract from PubMedRemoval of introns from transfer RNA precursors (pre-tRNAs) occurs in all living organisms. This is a vital phase in the maturation and functionality of tRNA. Here we present a 3.2 A-resolution cryo-EM structure of an active human tRNA splicing endonuclease complex bound to an intron-containing pre-tRNA. TSEN54, along with the unique regions of TSEN34 and TSEN2, cooperatively recognizes the mature body of pre-tRNA and guides the anticodon-intron stem to the correct position for splicing. We capture the moment when the endonucleases are poised for cleavage, illuminating the molecular mechanism for both 3' and 5' cleavage reactions. Two insertion loops from TSEN54 and TSEN2 cover the 3' and 5' splice sites, respectively, trapping the scissile phosphate in the center of the catalytic triad of residues. Our findings reveal the molecular mechanism for eukaryotic pre-tRNA recognition and cleavage, as well as the evolutionary relationship between archaeal and eukaryotic TSENs. Recognition and cleavage mechanism of intron-containing pre-tRNA by human TSEN endonuclease complex.,Yuan L, Han Y, Zhao J, Zhang Y, Sun Y Nat Commun. 2023 Sep 28;14(1):6071. doi: 10.1038/s41467-023-41845-y. PMID:37770519[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
Categories: Homo sapiens | Large Structures | Han Y | Sun Y | Yuan L | Zhang Y
