3NPN

Structure of the s-adenosylhomocysteine riboswitch at 3.0A

3NPN の概要

• エントリーDOI: 10.2210/pdb3npn/pdb
• 分子名称: S-ADENOSYLHOMOCYSTEINE RIBOSWITCH, S-ADENOSYL-L-HOMOCYSTEINE (2 entities in total)
• 機能のキーワード: rna, riboswitch, s-adenosyl-homocysteine
• 由来する生物種: Ralstonia solanacearum
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17882.93

構造登録者

Reyes, F.E.,Edwards, A.E.,Batey, R.T. (登録日: 2010-06-28, 公開日: 2010-10-06, 最終更新日: 2023-12-27)

主引用文献

Edwards, A.L.,Reyes, F.E.,Heroux, A.,Batey, R.T.
Structural basis for recognition of S-adenosylhomocysteine by riboswitches.
Rna, 16:2144-2155, 2010

PubMed Abstract: S-adenosyl-(L)-homocysteine (SAH) riboswitches are regulatory elements found in bacterial mRNAs that up-regulate genes involved in the S-adenosyl-(L)-methionine (SAM) regeneration cycle. To understand the structural basis of SAH-dependent regulation by RNA, we have solved the structure of its metabolite-binding domain in complex with SAH. This structure reveals an unusual pseudoknot topology that creates a shallow groove on the surface of the RNA that binds SAH primarily through interactions with the adenine ring and methionine main chain atoms and discriminates against SAM through a steric mechanism. Chemical probing and calorimetric analysis indicate that the unliganded RNA can access bound-like conformations that are significantly stabilized by SAH to direct folding of the downstream regulatory switch. Strikingly, we find that metabolites bearing an adenine ring, including ATP, bind this aptamer with sufficiently high affinity such that normal intracellular concentrations of these compounds may influence regulation of the riboswitch.

PubMed: 20864509
DOI: 10.1261/rna.2341610

実験手法

X-RAY DIFFRACTION (2.792 Å)