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Figure 1.
Figure 1. Structural properties of LIM4 and its sequence and
structural comparisons with other LIM domains. (a) Primary
sequence comparison of PINCH LIM domains. Residues in LIM1 and
LIM4 that are perturbed in HSQC spectra of free versus bound
protein (>100 Hz in LIM1 and >10 Hz in LIM4) are highlighted in
green. Zinc-coordinating residues are shown in red. Symbols at
the top indicate secondary structure elements in LIM4. (b)
Stereo view of best-fit superposition of 20 structures of LIM4
with the least NOE violations. (c) Zn2+ coordination. In the
top, Cys193, Cys196, His213 and His216 coordinate Zn2+ in the
N-terminal finger. In the bottom, Cys219, Cys222, Cys240 and
His243 coordinate Zn2+ in the C-terminal finger. (d) C  2
planes for His213, His216 and His243 (left to right) in 3D
15N,13C-edited NOESY spectrum showing NOE peaks (labels at
right) of imidazole ring H 2
atoms that unambiguously establish ring orientations for
Zn2+-coordinating histidines. (e) Best-fit superposition of
minimized average LIM4 (blue) with CRIP (red), showing the
relative twist between N- and C-terminal Zn-fingers in CRIP and
absence thereof in LIM4. Red spheres represent Zn2+ ions in
LIM4. The orientation is a 90° rotation about vertical axis
compared with b.
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