3E5C

Crystal Structure of the SMK box (SAM-III) Riboswitch with SAM

3E5C の概要

• エントリーDOI: 10.2210/pdb3e5c/pdb
• 関連するPDBエントリー: 3E5E 3E5F
• 分子名称: SMK box (SAM-III) Riboswitch, STRONTIUM ION, S-ADENOSYLMETHIONINE, ... (4 entities in total)
• 機能のキーワード: sam riboswitch smk sam-iii translation regulation sd, rna
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 19115.06

構造登録者

Lu, C. (登録日: 2008-08-13, 公開日: 2008-10-07, 最終更新日: 2024-02-21)

主引用文献

Lu, C.,Smith, A.M.,Fuchs, R.T.,Ding, F.,Rajashankar, K.,Henkin, T.M.,Ke, A.
Crystal structures of the SAM-III/S(MK) riboswitch reveal the SAM-dependent translation inhibition mechanism.
Nat.Struct.Mol.Biol., 15:1076-1083, 2008

PubMed Abstract: Three distinct classes of S-adenosyl-L-methionine (SAM)-responsive riboswitches have been identified that regulate bacterial gene expression at the levels of transcription attenuation or translation inhibition. The S(MK) box (SAM-III) translational riboswitch has been identified in the SAM synthetase gene in members of the Lactobacillales. Here we report the 2.2-A crystal structure of the Enterococcus faecalis S(MK) box riboswitch. The Y-shaped riboswitch organizes its conserved nucleotides around a three-way junction for SAM recognition. The Shine-Dalgarno sequence, which is sequestered by base-pairing with the anti-Shine-Dalgarno sequence in response to SAM binding, also directly participates in SAM recognition. The riboswitch makes extensive interactions with the adenosine and sulfonium moieties of SAM but does not appear to recognize the tail of the methionine moiety. We captured a structural snapshot of the S(MK) box riboswitch sampling the near-cognate ligand S-adenosyl-L-homocysteine (SAH) in which SAH was found to adopt an alternative conformation and fails to make several key interactions.

PubMed: 18806797
DOI: 10.1038/nsmb.1494

実験手法

X-RAY DIFFRACTION (2.25 Å)