4erl

Crystal structure of the lysine riboswitch bound to a lysine-glycine dipeptide

spinqualitylabelsall models 4erl, resolution 3.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4erl is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GLY, LYS Related: 3d0u, 3d0x, 4erj Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed A prevalent means of regulating gene expression in bacteria is by riboswitches found within mRNA leader sequences. Like protein repressors, these RNA elements must bind an effector molecule with high specificity against a background of other cellular metabolites of similar chemical structure to elicit the appropriate regulatory response. Current crystal structures of the lysine riboswitch do not provide a complete understanding of selectivity as recognition is substantially mediated through main-chain atoms of the amino acid. Using a directed set of lysine analogs and other amino acids, we have determined the relative contributions of the polar functional groups to binding affinity and the regulatory response. Our results reveal that the lysine riboswitch has >1000-fold specificity for lysine over other amino acids. The aptamer is highly sensitive to the precise placement of the epsilon-amino group and relatively tolerant of alterations to the main-chain functional groups in order to achieve this specificity. At low nucleotide triphosphate (NTP) concentrations, we observe good agreement between the half-maximal regulatory activity (T(50)) and the affinity of the receptor for lysine (K(d)), as well as many of its analogs. However, above 400muM [NTP], the concentration of lysine required to elicit transcription termination rises, moving into the riboswitch into a kinetic control regime. These data demonstrate that, under physiologically relevant conditions, riboswitches can integrate both effector and NTP concentrations to generate a regulatory response appropriate for global metabolic state of the cell. Insights into the Regulatory Landscape of the Lysine Riboswitch.,Garst AD, Porter EB, Batey RT J Mol Biol. 2012 Jul 3. PMID:22771573 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Riboswitch

Proteopedia Page Contributors and Editors (what is this?)

OCA