CLONING AND SEQUENCINGLACCASE 3 (Folac3) FROM FUSARIUM OXYSPORUM

Abstract

Laccases belong to the multi-copper oxidases family and catalyze the oxidation of a wide range of aromatic compounds in the presence of oxygen. Laccases have been widely used in various industries, especially in textiles and dyes industries, and the treatment of environmental pollutants. Laccase encoding gene from ascomycete fungus F. oxysporum HUIB02 was isolated through the PCR amplification using specific primers, resulting in a PCR product of 2 kb. The PCR product was cloned and sequenced. The result indicated Folac3 had a length of 1957 nu which comprised of 3 exons and 2 introns as well as encoded for a 617 aa protein. The primary analysis of the protein structure showed that Folac3 was an intracellular protein without a signal peptide sequence with 7 positions for N-glycosylation. The secondary structure analysis revealed that Folac3 had 6 α helices and 30 β sheets, while three dimension structure analysis showed that Folac3 was highly identical with a multi copper oxidase from S. cerevisiae. Our results would provide an important genetic source for further study on the heterologous expression as well as the application of recombinant laccase.