Azurin backbone

Fig. 2. Copper site in azurin. In this and subsequent figures the following conventions have been used, (a) The copper site is generally an enlargement of (b). The copper site is a dotted sphere, the ligand residues are represented by bonds connecting atoms in the side chain, and, where possible, the atoms bonded to the copper atom are identified by atom type. Ribbons represent portions of the backbone structure near the copper. In (b) of each figure, the main-chain polypeptide is represented by a ribbon fit to the main-chain coordinates, and the amino and carboxy termini are indicated by N and C, respectively, (c) A schematic version drawn from (b). Solid arrows represent main-chain regions participating in the /3 sheet roughly above the plane of the paper, while dotted or light arrows are the...

Fig. 21. Rmsd overlays of experimental (blue) and computed (yellow or CPK) backbone carbons (top) and active sites (bottom) for Amicyanin (left), Stellacyanin (middle), and Azurin (right) (PDB codes 1AAC, 1JER, 1DYZ).

Figure 3 Ribbon representation of the peptide backbone in P. aeruginosa azurin. The Cu cofactor and its hgands are shown in black...

Figure 1 (Chapter 1). Three-dimensional structure of Pseudomonas aeruginosa azurin (16). In addition to the protein backbone, the side chains of three copper ligating residues, His46, HisllT, and Cysll2 are shown near the top together with the disulfide bridge (bottom) and Trp48 (center). Coordinates were taken from the Protein Data Bank (PDB), code 4AZU.

Single-crystal structural data have provided valuable information about blue copper proteins containing Type 1 Cu centres. Figure 28.10a shows a representation of the folded protein chain of spinach plastocyanin. The Cu(II) centre lies within a pocket in the chain, bound by a Cys, a Met and two His residues (Figure 28.10b) the S(Met) atom is significantly further away from the Cu(II) centre than is S(Cys). Figure 28.10c shows the backbone of the protein chain in azurin isolated from the bacterium Pseudomonas putida. The coordination environment of the Cu(II) centre resembles that in plastocyanin with Cu—S(Met) > Cu—S(Cys), but in addition, an O atom from an adjacent Gly residue is involved in a weak coordinate interaction (Figure 28.10d). Structural... 

O Fig. 28.10 The structure of spinach plastocyanin (a) the backbone of the protein chain showing the position of the Cu(II) centre and (b) the coordination sphere of the Cu(II) centre, consisting of one methionine, one cysteine and two histidine residues. The structure of azurin from Pseudomonas putida (c) the backbone of the protein chain showing the position of the Cu(II) centre and (d) the Cu(II) centre, coordinated by a methionine, a cysteine and two histidine residues one O atom from the glycine residue adjacent to one of the histidines interacts weakly with the metal centre (the red hashed line). Hydrogen atoms are omitted colour code Cu, brown S, yellow C, grey N, blue O, red. 

Figure 1. Three-dimensional structure of the polypeptide backbone o/Pseudomo-nas aeruginosa azurin, with some amino add residues of particular interest included. Coordinates were obtained from reference 21.

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