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Figure 1.
Fig. 1. Crystal structure and electron-density map (2F[o]
− F[c]) of cytochrome c[6A] from Arabidopsis thaliana. (A) The
four protein molecules in the asymmetric unit of A. thaliana
cytochrome c[6A]. (B) Final electron-density map around the zinc
ion and neighboring residues contoured at 1.2 σ. (C) Cross-eyes
stereo image of the overall strucrure of A. thaliana cytochrome
c[6A]. (D) Superimposion of A. thaliana cytochrome c[6A] (red)
and red alga P. yezoensis cytochrome c[6A] (blue). (E) The final
electron-density map (2F[o] − F[c]) around the characteristic
12 amino acids loop contoured at 1.2 σ. A is represented by a
Cα trace with an attached heme group. Four protein molecules
were displayed by one molecule with a different color (red,
green, yellow and cyan), respectively. The zinc is represented
by sphere model with gray color. B and E the heme and amino acid
residues are represented by ball-and-stick models with
atom-specific colors: yellow, carbon; cyan, nitrogen; red,
oxygen; orange, iron; green, sulfur; gray, zinc. C, The
α-helices (blue), β-sheet (green) and the characteristic 12
amino acids loop (red) are indicated as thick ribbons. The
Cys16, Cys19, His20, Met60, Cys67, Cys73 and heme are
represented by ball-and-stick in the same coloring scheme as B
and E. D, The superimposition was calculated using lsqkab in
CCP4. The structure is superimposed by a rigid body rotation and
translation that minimized the root-mean-square difference
between their main chain Cα atoms.
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