A new multicopper oxidase gene AaMco1 was identified from Acidomyces acidophilus, a pigmented extremophile ascomycete that was isolated originally from acidic water. Sequence analysis revealed that it encodes a 682 amino acid protein with an apparent molecular mass of 85 kDa as determined by denaturing SDS-PAGE. AaMco1 shows interesting characteristics: it has an N-terminal transmembrane helix and no signal peptide. To obtain an active and soluble protein, AaMco1 was truncated at its N-terminal to remove the transmembrane helix, but even in this form the protein was found in the insoluble fraction. AaMco1 and its truncated form were then denatured, purified and renatured before characterization. Structural analysis and protein characterization by enzymatic assays indicate that AaMco1 has ferroxidase activity and could be part of a new phylogenetic branch, the ascomycete MCO family, described for the first time here.
Identification et caractérisation d’une nouvelle multicopper oxydase chez Acidomyces acidophilus
Boonen, F. (Author). 6 Sept 2012
Student thesis: Doc types › Doctor of Sciences