3npq

Structure of the S-adenosylhomocysteine riboswitch at 2.18 AStructure of the S-adenosylhomocysteine riboswitch at 2.18 A

Structural highlights 3npq is a 3 chain structure with sequence from Ralstonia solanacearum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1814Å Ligands: , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed 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. Structural basis for recognition of S-adenosylhomocysteine by riboswitches.,Edwards AL, Reyes FE, Heroux A, Batey RT RNA. 2010 Sep 23. PMID:20864509 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Mitogen-activated protein kinase 3D structures Riboswitch 3D structures

spinqualitylabelsall models 3npq, resolution 2.18Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image