Pseudoazurin source

There are a number of excellent sources of information on copper proteins notable among them is the three-volume series Copper Proteins and Copper Enzymes (Lontie, 1984). A review of the state of structural knowledge in 1985 (Adman, 1985) included only the small blue copper proteins. A brief review of extended X-ray absorption fine structure (EXAFS) work on some of these proteins appeared in 1987 (Hasnain and Garner, 1987). A number of new structures have been solved by X-ray diffraction, and the structures of azurin and plastocyanin have been extended to higher resolution. The new structures include two additional type I proteins (pseudoazurin and cucumber basic blue protein), the type III copper protein hemocyanin, and the multi-copper blue oxidase ascorbate oxidase. Results are now available on a copper-containing nitrite reductase and galactose oxidase. 

Pseudoazurins are found in bacteria which under limited oxygen conditions are capable of using nitrate/nitrite as an energy source. They are key components of the electron-transfer chain that sequentially reduces N03 /N02 to... 

Amicyanin is found in methylotrophic bacteria that can use methylated amines as an energy source. The inactivation of the amicyanin gene in Paracoccus denitrificans results in complete loss of its ability to grow on methylamine, a direct indication that amicyanin is a key component of the methylamine driven electron-transfer chain. Amicyanin accepts an electron from methylamine dehydrogenase and transfers it to a c-type cytochrome (see Section 5.4.5). Currently, more than a dozen amicyanin and pseudoazurin sequences are available. 

Other small green copper proteins include pseudoazurin and auracyanin. Pseudoazurins have been isolated from methylotrophic and denitrifying bacteria. In methylotrophs, while amicyanins are synthesized when methylamine is the sole source of carbon and energy. 

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