Figure 2.
Figure 2 (A) Structure of CBP20 in the CBC NLS
complex. Ribbon representation of the cap-free conformation of
CBP20 showing residues 30−125 (grey). Residues involved in cap
binding are shown in yellow (already in their cap-bound
conformation) and blue (undergo a conformational change to
interact with the cap) (compare with B). Phe49 (light green)
changes conformation to help stabilize the C-terminal domain
(compare with B). Salt bridges and hydrogen bonds are indicated
by dashed lines. (B) Stabilization of the N- and C-terminal
extensions of CBP20 upon cap binding. Ribbon representation of
cap-bound CBP20 showing residues 32−125 (already ordered in
the cap-free form) in grey and the N- and C-terminal extensions
that fold upon cap binding in green and orange, respectively.
Yellow residues stabilize the folded conformation of these two
extensions through interactions with the cap. This stabilization
is reinforced by protein−protein interactions involving the
light green residues. D116, R123 and R127 take part to both
kinds of contacts. CBP80 residues interacting with residues
5−13 from CBP20 are depicted in pink. Hydrogen bonds and salt
bridges are represented as dashed lines, and the hydrophobic
contacts as dashed bars. (C and D) Two views of CBC bound to the
cap analogue m^7GpppG. The three MIF4G domains of CBP80 are
represented in pink, yellow and green for domains 1, 2 and 3,
respectively. CBP20 is depicted in red, and the cap analogue
m^7GpppG in cyan. (A), (B) and (C) were generated with Molscript
(Kraulis, 1991) and Render (Merritt and Murphy, 1994).
The above figure is reprinted
from an Open Access publication published by Macmillan Publishers Ltd:
EMBO J
(2002,
21,
5548-5557)
copyright 2002.
NLS
complex. Ribbon representation of the cap-free conformation of
CBP20 showing residues 30−125 (grey). Residues involved in cap
binding are shown in yellow (already in their cap-bound
conformation) and blue (undergo a conformational change to
interact with the cap) (compare with B). Phe49 (light green)
changes conformation to help stabilize the C-terminal domain
(compare with B). Salt bridges and hydrogen bonds are indicated
by dashed lines. (B) Stabilization of the N- and C-terminal
extensions of CBP20 upon cap binding. Ribbon representation of
cap-bound CBP20 showing residues 32−125 (already ordered in
the cap-free form) in grey and the N- and C-terminal extensions
that fold upon cap binding in green and orange, respectively.
Yellow residues stabilize the folded conformation of these two
extensions through interactions with the cap. This stabilization
is reinforced by protein−protein interactions involving the
light green residues. D116, R123 and R127 take part to both
kinds of contacts. CBP80 residues interacting with residues
5−13 from CBP20 are depicted in pink. Hydrogen bonds and salt
bridges are represented as dashed lines, and the hydrophobic
contacts as dashed bars. (C and D) Two views of CBC bound to the
cap analogue m^7GpppG. The three MIF4G domains of CBP80 are
represented in pink, yellow and green for domains 1, 2 and 3,
respectively. CBP20 is depicted in red, and the cap analogue
m^7GpppG in cyan. (A), (B) and (C) were generated with Molscript
(Kraulis, 1991) and Render (Merritt and Murphy, 1994).