Figure 1.
Figure 1 Structure and ion-binding properties of the EcClC
selectivity filter. (A) View of a ribbon representation of the
EcClC dimer from within the membrane. The subunits are colored
in green and blue. The ions are represented as red spheres. The
region of the selectivity filter in one subunit is indicated by
a transparent gray box. (B) Selectivity filter of wtEcClC
(closed) and the EcClC mutant E148Q (open) viewed from the dimer
interface. The protein backbone is shown as a ribbon, with
selected residues as sticks. The N-terminal ends of -helices
are colored in cyan. The ions are represented as red spheres.
The Br- anomalous difference density (contoured at 6 )
is shown superimposed (red). The path for sampling the anomalous
difference density is shown as gray lines (open). Aqueous
cavities from the extracellular solution (out) and intracellular
solution (in) are shown as cyan mesh. The ion-binding sites are
labeled. (A) and (B) were prepared with DINO (www.dino3d.org).
(C) One-dimensional anomalous difference electron density in the
selectivity filter at high Br- concentration. The density ( )
is plotted in units of its standard deviation. The filter
position is shown relative to S[cen]. The curve for the 'open
conformation' is colored in blue, the curve for the 'closed
conformation' in red.
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
EMBO J
(2006,
25,
24-33)
copyright 2006.
-helices
are colored in cyan. The ions are represented as red spheres.
The Br- anomalous difference density (contoured at 6 
)
is shown superimposed (red). The path for sampling the anomalous
difference density is shown as gray lines (open). Aqueous
cavities from the extracellular solution (out) and intracellular
solution (in) are shown as cyan mesh. The ion-binding sites are
labeled. (A) and (B) were prepared with DINO (www.dino3d.org).
(C) One-dimensional anomalous difference electron density in the
selectivity filter at high Br- concentration. The density ( 
)
is plotted in units of its standard deviation. The filter
position is shown relative to S[cen]. The curve for the 'open
conformation' is colored in blue, the curve for the 'closed
conformation' in red.