Cover image

G96A mutant of the PRPP riboswitch from T. mathranii bound to ppGpp (Protein Data Bank code: 6ck4; Knappenberger AJ, Reiss CW, Strobel SA. 2018. Structures of two aptamers with differing ligand specificity reveal ruggedness in the functional landscape of RNA. Elife 7: e36381). The RNA riboswitch backbone is displayed as a red ribbon; bases are shown as blocks with NDB coloring: A—red, C—yellow, G—green, U—cyan; ppGpp and GTP ligands are shown in spacefill with element colors: C—white, N—blue, O—red, P—orange. The image was generated using 3DNA/blocview and PyMol software. Cover image provided by the Nucleic Acid Database (ndbserver.rutgers.edu).