Figure 1.
Figure 1: Overall structure and long-range tertiary interactions
of the lysine-bound T. maritima riboswitch. a, Schematic of
the riboswitch fold observed in the crystal structure of the
complex. The bound lysine is in red. The RNA domains are
depicted in colours used for subsequent figures. Base-specific
tertiary contacts and long-range stacking interactions are shown
as thin green and thick blue dashed lines, respectively.
Nucleotides invariant in known lysine riboswitches are boxed. b,
c, Overall lysine riboswitch structure in a ribbon
representation showing front (b) and rotated by 60°
(c) views. d, The L2–L3 kissing loop interaction is formed by
six base pairs, supplemented by interstrand stacking
interactions between A42 and C95, G43 and U94, and G44 and G101.
Hydrogen bonds between interstrand base pairs and orthogonally
aligned G43 and U94 bases are depicted by dashed lines. e, The
L4-loop–P2-helix interaction formed by an insertion of the
A126–A127–A129 stack of L4 into the RNA groove of P2
distorted by non-canonical base pairs.
60°
(c) views. d, The L2–L3 kissing loop interaction is formed by
six base pairs, supplemented by interstrand stacking
interactions between A42 and C95, G43 and U94, and G44 and G101.
Hydrogen bonds between interstrand base pairs and orthogonally
aligned G43 and U94 bases are depicted by dashed lines. e, The
L4-loop–P2-helix interaction formed by an insertion of the
A126–A127–A129 stack of L4 into the RNA groove of P2
distorted by non-canonical base pairs.