Structural insights into group II intron catalysis and branch-site selection
Structural insights into group II intron catalysis and branch-site selection
复制标题
DOI：
10.1126/science.1069268
复制
发表时间：
2002-03-15
期刊：
影响因子：
56.9
通讯作者：
Doudna, JA
中科院分区：
文献类型：
--
作者：
Zhang, L;Doudna, JA
第二类自剪接内含子催化从前体RNA转录物中自动切割，其机制与剪接体惊人地相似，剪接体是一种RNA-蛋白质组装，负责将大多数真核细胞前-mRNAs的蛋白质编码部分剪接在一起。在这两种情况下，剪接都是通过保守内含子腺苷残基的2‘OH对5’剪接位点的亲核攻击而启动的，从而产生分支(套索)中间体。在这里，我们描述了一个70个核苷酸的RNA在3.0埃分辨率下的晶体结构，该RNA包含酵母AI5Gamma组II自剪接内含子的催化必需结构域5和6，揭示了结构域6中分支点腺苷周围意想不到的两核苷酸膨胀结构。
Group II self-splicing introns catalyze autoexcision from precursor RNA transcripts by a mechanism strikingly similar to that of the spliceosome, an RNA-protein assembly responsible for splicing together the protein-coding parts of most eukaryotic pre-mRNAs. Splicing in both cases initiates via nucleophilic attack at the 5' splice site by the 2' OH of a conserved intron adenosine residue, creating a branched (lariat) intermediate. Here, we describe the crystal structure at 3.0 Angstrom resolution of a 70-nucleotide RNA containing the catalytically essential domains 5 and 6 of the yeast ai5gamma group II self-splicing intron, revealing an unexpected two-nucleotide bulged structure around the branch-point adenosine in domain 6.