Isolation of arasgene from the basidiomyceteCoriolus hirsutusand use of its promoter for the expression ofPleurotus ostreatusmanganese(II) peroxidase cDNA inC. hirsutus.

Arasgene homologue (namedCh.ras) was cloned from the basidiomyceteCoriolus hirsutus.Ch.rashas a coding capacity of 215 amino acids (aa) interrupted by six small introns. The deduced Ch.Ras protein exhibited significant homology (86.5% or 86.0% identical) to the basidiomyceteCoprinus cinereusRas (215 aa) andLentinula edodesRas (217 aa) proteins. The 5'-upstream region ofCh.rascontains two GC boxlike sequences, one TATA boxlike sequence, one CCAAT box, and three CT-rich sequences. Primer extension analysis showed the presence of three transcriptional initiation sites: one is located in the most upstream CT-sequence and the other two just after it. By using the 1.4-kb fragment containing the promoter elements and transcriptional initiation sites, we have constructed the chromosome-integrating vector pHRP, which is useful for the expression of foreign genes inC. hirsutus. ThePleurotus ostreatusmanganese(II) peroxidase (MnP) cDNA (designatedmnpc) was inserted into the downstream of theCh.raspromoter elements of pHRP, yielding pHRP-mnp. We obtained, with pHRP-mnp,C. hirsutusstrains that show high levels of enzymatic activity of MnP and efficiently degrade pentachlorophenol (PCP), a chlorinated aromatic toxic compound. [ABSTRACT FROM AUTHOR]