Crystal structures of E. coli laccase CueO at different copper concentrations.
CueO protein is a hypothetical bacterial laccase and a good laccase candidate for large scale industrial application. Four CueO crystal structures were determined at different copper concentrations. Low copper occupancy in apo-CueO and slow copper reconstitution process in CueO with exogenous copper were demonstrated. These observations well explain the copper dependence of CueO oxidase activity. Structural comparison between CueO and other three fungal laccase proteins indicates that Glu106 in CueO constitutes the primary counter-work for reconstitution of the trinuclear copper site. Mutation of Glu106 to a Phe enhanced CueO oxidation activity and supported this hypothesis. In addition, an extra alpha-helix from Leu351 to Gly378 covers substrate biding pocket of CueO and might compromises the electron transfer from substrate to type I copper.
Li
Xu
X
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, People's Republic of China.
Wei
Zhiyi
Z
Zhang
Min
M
Peng
Xiaohui
X
Yu
Guangzhe
G
Teng
Maikun
M
Gong
Weimin
W
D000595:Amino Acid Sequence; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D042845:Laccase / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry* / Q000648:ultrastructure*; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D029968:Escherichia coli Proteins; D003300:Copper; D010088:Oxidoreductases; C499679:cueO protein, E coli; D042845:Laccase