4X4W
Crystal structure of the full-length human mitochondrial CCA-adding enzyme
Summary for 4X4W
| Entry DOI | 10.2210/pdb4x4w/pdb |
| Descriptor | CCA tRNA nucleotidyltransferase 1, mitochondrial, SULFATE ION, CITRATE ANION, ... (6 entities in total) |
| Functional Keywords | protein-rna complex, trna, non-coding rna, cca-adding enzyme, nucleotidyltransferase, ncrna, rna binding protein |
| Biological source | Homo sapiens (Human) |
| Total number of polymer chains | 2 |
| Total formula weight | 97449.82 |
| Authors | Kuhn, C.-D.,Joshua-Tor, L. (deposition date: 2014-12-03, release date: 2015-02-11, Last modification date: 2023-12-27) |
| Primary citation | 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 Cited by 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: 25640237DOI: 10.1016/j.cell.2015.01.005 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.9 Å) |
Structure validation
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