A pirin-like protein from Pseudomonas stutzeri and its quercetinase activity

A pirin-like protein from a marine denitrifying bacterium, Pseudomonas stutzeri Zobell has been heterologously expressed in E. coli and purified to homogeneity with metal-affinity and gel filtration chromatographies. The recombinant pirin-like protein has exhibited quercetinase activities upon the incorporation of a divalent metal ion, while its biological role remains unclear. In the case of Cu(2+) the holo-protein demonstrated the highest activities and spectroscopic properties typical of type II Cu protein. A 3D-structual model constructed using the crystal structure of human pirin as temperate indicated that the metal biding site is constructed with 3His1Glu located in the consensus sequences in the N-terminal domain.