Galactose oxidase domain structure

In early 1990 it became apparent that the structure of galactose oxidase from Dactylium dendroides was about to emerge. A 2.5 A multiple isomor-phous replacement (MIR) map based on area detector data from a native and three derivative crystals yielded a polypeptide chain tracing. The refined structure at 1.9 A (R = 0.179) (Ito et al., 1991) shows that galactose oxidase consists of three domains, each of which is predominandy jS... 

Fig. 2. Structure of galactose oxidase. (Top) View along axis of Domain II. (Bottom) View perpendicular to the wheel axis. The location of the active site copper is indicated by a black dot ).

The three-dimensional structure of galactose oxidase consists almost entirely of /1-strands only a single, short a-helix (residues 328-331) occurs. The enzyme can be divided into three domains domain 1 (residues 1-155), domain 2 (residues 156-532), and domain 3 (residues 533-639) (Fig. 22) [30]. 

The crystal structure of galactose oxidase from the fungus Dactylium dendroides has been determined. Accordingly, galactose oxidase (639 amino acid residues) consists of three domains predominantly formed from /3-structures (Figure 14). The first domain (residues 1-155) has a /3-sandwich structure. The catalytic domain (residues 156-532) comprises a seven-fold /3-propeller based on the kelch structural motif The copper lies on the solvent-accessible surface of this domain close to the pseudo seven-fold axis. The third domain (residues 533-639) is comprised of seven /3-strands. The copper site on the second domain lies in a region extremely rich... 

Other P-sheet proteins. Influenza neuraminidase contains an unusual P-sheet propeUer-like structure (Figure 5.10E). Ascorbate oxidase and galactose oxidase are laige P-sheet proteins that contain parallel P-sheet domains in a jeUyroU- or sandwich-like structure. 

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