3NPQ
Structure of the S-adenosylhomocysteine riboswitch at 2.18 A
Summary for 3NPQ
| Entry DOI | 10.2210/pdb3npq/pdb |
| Descriptor | S-ADENOSYLHOMOCYSTEINE RIBOSWITCH, S-ADENOSYL-L-HOMOCYSTEINE, COBALT HEXAMMINE(III), ... (4 entities in total) |
| Functional Keywords | rna, riboswitch, s-adenosyl-homocysteine |
| Biological source | Ralstonia solanacearum |
| Total number of polymer chains | 3 |
| Total formula weight | 56038.50 |
| Authors | Reyes, F.E.,Edwards, A.E.,Batey, R.T. (deposition date: 2010-06-28, release date: 2010-10-06, Last modification date: 2023-09-06) |
| Primary citation | 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 Cited by 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: 20864509DOI: 10.1261/rna.2341610 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1814 Å) |
Structure validation
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