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Figure 2.
Figure 2. ATP binding to the N-domain of NaK  1.
(a) Titration curves for ATP (red), ADP (green) and MgATP
(blue) giving K[d] values of 5.1, 24.2 and 25.1 mM,
respectively, with standard deviations of  0.4,
5.3 and 8.6, respectively. (b) Mapping of chemical shift changes
on the molecular surface of the N-domain of NaK  1.
The color code reflects the normalized weighted average of the
1H and 15N chemical shifts calculated as ((   2[NH]
+ 2[N]
/ 25) / 2)1/2 / [max],
where [max]
is the maximum observed weighted shift difference in p.p.m.38.
The most significant changes are in red and the moderate changes
in yellow. (c) The ATP-binding pocket displaying one of the
energy-minimized CYANA conformers with ATP and amino acids
critical for ATP binding in ball-and-stick representation. (d)
Stereo view of the conformational changes at the N and C termini
in response to ATP binding. The ATP-bound form of the N-domain
is colored blue; the native form of the protein is colored
yellow. Binding of ATP (shown in ball and stick; carbon atoms,
black; nitrogen, blue; oxygen, red; and phosphorons, magenta)
causes a displacement of strands  1
and 6.
The disordered loop between residues 391 -408 has been removed
for clarity.
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