2M12

Solution structure of the ID3 stem loop of domain 1 of the ai5gamma group II intron

2M12 の概要

• エントリーDOI: 10.2210/pdb2m12/pdb
• NMR情報: BMRB: 18838
• 分子名称: RNA (5'-R(*GP*GP*GP*UP*GP*UP*AP*UP*UP*GP*GP*AP*AP*AP*UP*GP*AP*GP*CP*AP*CP*CP*C)-3') (1 entity in total)
• 機能のキーワード: ebs1, stem loop, id3, rna
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7443.48

構造登録者

Popovic, M.,Greenbaum, N.L. (登録日: 2012-11-13, 公開日: 2013-10-23, 最終更新日: 2024-05-15)

主引用文献

Popovic, M.,Greenbaum, N.L.
Role of helical constraints of the EBS1-IBS1 duplex of a group II intron on demarcation of the 5' splice site.
Rna, 20:24-35, 2014

PubMed Abstract: Recognition of the 5' splice site by group II introns involves pairing between an exon binding sequence (EBS) 1 within the ID3 stem-loop of domain 1 and a complementary sequence at the 3' end of exon 1 (IBS1). To identify the molecular basis for splice site definition of a group IIB ai5γ intron, we probed the solution structure of the ID3 stem-loop alone and upon binding of its IBS1 target by solution NMR. The ID3 stem was structured. The base of the ID3 loop was stacked but displayed a highly flexible EBS1 region. The flexibility of EBS1 appears to be a general feature of the ai5γ and the smaller Oceanobacillus iheyensis (O.i.) intron and may help in effective search of conformational space and prevent errors in splicing as a result of fortuitous base-pairing. Binding of IBS1 results in formation of a structured seven base pair duplex that terminates at the 5' splice site in spite of the potential for additional A-U and G•U pairs. Comparison of these data with conformational features of EBS1-IBS1 duplexes extracted from published structures suggests that termination of the duplex and definition of the splice site are governed by constraints of the helical geometry within the ID3 loop. This feature and flexibility of the uncomplexed ID3 loop appear to be common for both the ai5γ and O.i. introns and may help to fine-tune elements of recognition in group II introns.

PubMed: 24243113
DOI: 10.1261/rna.039701.113

実験手法

SOLUTION NMR