title: X-ray structure of a two-domain type laccase: a missing link in the evolution of multi-copper proteins.
abstract: A multi-copper protein with two cupredoxin-like domains was identified from our in-house metagenomic database. The recombinant protein, mgLAC, contained four copper ions/subunits, oxidized various phenolic and non-phenolic substrates, and had spectroscopic properties similar to common laccases. X-ray structure analysis revealed a homotrimeric architecture for this enzyme, which resembles nitrite reductase (NIR). However, a difference in copper coordination was found at the domain interface. mgLAC contains a T2/T3 tri-nuclear copper cluster at this site, whereas a mononuclear T2 copper occupies this position in NIR. The trimer is thus an essential part of the architecture of two-domain multi-copper proteins, and mgLAC may be an evolutionary precursor of NIR.
authors.affiliation: Department of Life Science, Graduate School of Life Science, University of Hyogo and Himeji Institute of Technology, Ako-gun, Hyogo 678-1297, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Komori
authors.forename: Kentaro
authors.initials: K
authors.lastname: Miyazaki
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Higuchi
mesh_terms: D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D030562:Databases, Protein; D019143:Evolution, Molecular; D042845:Laccase / Q000737:chemistry* / Q000235:genetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D020836:Protein Structure, Quaternary / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D003300:Copper; D042845:Laccase