Introduction of a Cu A site into the blue copper protein amicyanin from Thiobacillus versutus

Abstract

The C-terminal loop of the blue copper protein amicyanin, which contains three of the four active site ligands, has been replaced with a Cu A binding loop. The purple protein produced has visible and EPR spectra identical to those of a Cu A centre. Recent evidence strongly suggests that the Cu A centre of cytochrome c oxidase and the A centre of nitrous oxide reductase are similar and are both binuclear. It therefore follows that the purple amicyanin mutant created here also possesses a binuclear Cu A centre.