3OUY

How the CCA-adding Enzyme Selects Adenine Over Cytosine at Position 76 of tRNA

3OUY の概要

• エントリーDOI: 10.2210/pdb3ouy/pdb
• 関連するPDBエントリー: 3OV7 3OVA 3OVB 3OVS
• 分子名称: CCA-Adding Enzyme, RNA (35-MER), SULFATE ION, ... (7 entities in total)
• 機能のキーワード: protein-rna complex, rossmann fold, cca-adding, trna, phospholation, transferase-rna complex, transferase/rna
• 由来する生物種: Archaeoglobus fulgidus; 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 126414.38

構造登録者

Pan, B.C.,Xiong, Y.,Steitz, T.A. (登録日: 2010-09-15, 公開日: 2010-12-01, 最終更新日: 2024-02-21)

主引用文献

Pan, B.,Xiong, Y.,Steitz, T.A.
How the CCA-Adding Enzyme Selects Adenine over Cytosine at Position 76 of tRNA.
Science, 330:937-940, 2010

PubMed Abstract: CCA-adding enzymes [ATP(CTP):tRNA nucleotidyltransferases] add CCA onto the 3' end of transfer RNA (tRNA) precursors without using a nucleic acid template. Although the mechanism by which cytosine (C) is selected at position 75 of tRNA has been established, the mechanism by which adenine (A) is selected at position 76 remains elusive. Here, we report five cocrystal structures of the enzyme complexed with both a tRNA mimic and nucleoside triphosphates under catalytically active conditions. These structures suggest that adenosine 5'-monophosphate is incorporated onto the A76 position of the tRNA via a carboxylate-assisted, one-metal-ion mechanism with aspartate 110 functioning as a general base. The discrimination against incorporation of cytidine 5'-triphosphate (CTP) at position 76 arises from improper placement of the α phosphate of the incoming CTP, which results from the interaction of C with arginine 224 and prevents the nucleophilic attack by the 3' hydroxyl group of cytidine75.

PubMed: 21071662
DOI: 10.1126/science.1194985

実験手法

X-RAY DIFFRACTION (2.69 Å)