3GX6

Crystal structure of the T. tengcongensis SAM-I riboswitch variant U34C/A94G bound with SAM in manganese chloride

3GX6 の概要

• エントリーDOI: 10.2210/pdb3gx6/pdb
• 関連するPDBエントリー: 3GX2 3GX3 3GX5 3GX7
• 分子名称: RNA (94-MER), S-ADENOSYLMETHIONINE, MANGANESE (II) ION (3 entities in total)
• 機能のキーワード: kink-turn, four-way junction, pseudoknot, riboswitch, rna
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 31241.47

構造登録者

Montange, R.K.,Batey, R.T. (登録日: 2009-04-01, 公開日: 2010-01-12, 最終更新日: 2023-09-06)

主引用文献

Montange, R.K.,Mondragon, E.,van Tyne, D.,Garst, A.D.,Ceres, P.,Batey, R.T.
Discrimination between Closely Related Cellular Metabolites by the SAM-I Riboswitch.
J.Mol.Biol., 396:761-772, 2010

PubMed Abstract: The SAM-I riboswitch is a cis-acting element of genetic control found in bacterial mRNAs that specifically binds S-adenosylmethionine (SAM). We previously determined the 2.9-A X-ray crystal structure of the effector-binding domain of this RNA element, revealing details of RNA-ligand recognition. To improve this structure, variations were made to the RNA sequence to alter lattice contacts, resulting in a 0.5-A improvement in crystallographic resolution and allowing for a more accurate refinement of the crystallographic model. The basis for SAM specificity was addressed by a structural analysis of the RNA complexed to S-adenosylhomocysteine (SAH) and sinefungin and by measuring the affinity of SAM and SAH for a series of mutants using isothermal titration calorimetry. These data illustrate the importance of two universally conserved base pairs in the RNA that form electrostatic interactions with the positively charged sulfonium group of SAM, thereby providing a basis for discrimination between SAM and SAH.

PubMed: 20006621
DOI: 10.1016/j.jmb.2009.12.007

実験手法

X-RAY DIFFRACTION (2.8 Å)