Primary structure of a Japanese lacquer tree laccase as a prototype enzyme of multicopper oxidases.
The cDNA library of the Japanese lacquer tree (Rhus vernicifera) was constructed by the reverse transcription of mRNA. A cDNA encoding laccase was amplified by PCR using primers based on the N-terminal amino acid sequences of the purified laccase and its peptide fragments formed by digestions with chymotrypsin and trypsin, and subcloned. The laccase cDNA clone contained a single, large open reading frame of 1599 nucleotides, encoding a protein of 533 amino acids with a calculated molecular mass of 58981 Da. The lacquer laccase was found to have 42 to 62% identity with other plant laccases and 20 to 24% identity with microorganism laccases at the deduced amino acid level. Differing from microorganism laccases the lacquer laccase utilizes a Met residue in addition to one Cys and two His residues to construct the type 1 Cu site. The secondary structure of the lacquer laccase was predicted to mainly consist of the beta-structure (28.7%) and loop and random structures (67.0%). The alpha-helix content was predicted to be only 4.3%. The location of these secondary structures was assumed to be very similar to those of ascorbate oxidase and fungal laccase, the crystal structures of which have been determined.
Nitta
Kazutomo
K
Department of Chemistry, Faculty of Science, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan.
Kataoka
Kunishige
K
Sakurai
Takeshi
T
D000595:Amino Acid Sequence; D001483:Base Sequence; D003300:Copper / Q000737:chemistry*; D006801:Humans; D042845:Laccase; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry* / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D017433:Protein Structure, Secondary; D029045:Rhus / Q000201:enzymology*; D016415:Sequence Alignment; D014197:Trees
D010940:Plant Proteins; D003300:Copper; D010088:Oxidoreductases; D042845:Laccase