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Figure 1.
Figure 1. Overview of Substrate-Bound H/ACA RNP Structures
(A) Secondary structure of H/ACA RNA1 with substrate RNA
bound at the pseudouridylation pocket. The lower (P1) and upper
(P2) stems, substrate-guide helices PS1 and PS2, and the lower
(J1) and upper (J2) three-way junctions are indicated. Base pair
symbols are depicted according to a previous rule (Leontis and
Westhof, 2001). Hollow letters represent disordered residues in
the Gar-minus structure. Prime denotes substrate RNA.
(B)
Ribbon representation of the substrate-bound Gar1-minus H/ACA
RNP structure, showing Cbf5 PUA domain in light green; Cbf5
catalytic (Cat) domain in dark green; Nop10 in magenta; L7Ae in
blue; substrate RNA in purple; guide sequences in orange; the
ACA motif, kink-turn motif, and target nucleotide in red; and
the remainder of the H/ACA RNA in yellow. The target nucleotide
is shown as sticks.
(C) SIGMAA-weighted 2F[o] − F[c]
electron density map of the Gar1-minus complex. The 2.1 Å
map is contoured at 1 σ. The refined structure is shown as
sticks with carbon atoms colored in pink, oxygen in red,
nitrogen in blue, phosphorus in orange, and magnesium in green.
(D) The substrate-bound full-complex structure represented
as Cα or P traces. The solvent-modified 5 Å electron
density map contoured at 1 σ is indicated. Gar1 is colored
cyan, and other parts are color coded as in Figure 1B. A
symmetry-related molecule, colored in gray, forms a self-duplex
with the 5′ extension of H/ACA RNA2.
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