4X4W

Crystal structure of the full-length human mitochondrial CCA-adding enzyme

4X4W の概要

• エントリーDOI: 10.2210/pdb4x4w/pdb
• 分子名称: CCA tRNA nucleotidyltransferase 1, mitochondrial, SULFATE ION, CITRATE ANION, ... (6 entities in total)
• 機能のキーワード: protein-rna complex, trna, non-coding rna, cca-adding enzyme, nucleotidyltransferase, ncrna, rna binding protein
• 由来する生物種: Homo sapiens (Human)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 97449.82

構造登録者

Kuhn, C.-D.,Joshua-Tor, L. (登録日: 2014-12-03, 公開日: 2015-02-11, 最終更新日: 2023-12-27)

主引用文献

Kuhn, C.D.,Wilusz, J.E.,Zheng, Y.,Beal, P.A.,Joshua-Tor, L.
On-Enzyme Refolding Permits Small RNA and tRNA Surveillance by the CCA-Adding Enzyme.
Cell, 160:644-658, 2015

PubMed Abstract: Transcription in eukaryotes produces a number of long noncoding RNAs (lncRNAs). Two of these, MALAT1 and Menβ, generate a tRNA-like small RNA in addition to the mature lncRNA. The stability of these tRNA-like small RNAs and bona fide tRNAs is monitored by the CCA-adding enzyme. Whereas CCA is added to stable tRNAs and tRNA-like transcripts, a second CCA repeat is added to certain unstable transcripts to initiate their degradation. Here, we characterize how these two scenarios are distinguished. Following the first CCA addition cycle, nucleotide binding to the active site triggers a clockwise screw motion, producing torque on the RNA. This ejects stable RNAs, whereas unstable RNAs are refolded while bound to the enzyme and subjected to a second CCA catalytic cycle. Intriguingly, with the CCA-adding enzyme acting as a molecular vise, the RNAs proofread themselves through differential responses to its interrogation between stable and unstable substrates.

PubMed: 25640237
DOI: 10.1016/j.cell.2015.01.005

実験手法

X-RAY DIFFRACTION (1.9 Å)