The white rot basidiomycete Phanerochaete chrysosporium is able to efficiently degrade all major components of wood: cellulose, lignin and hemicellulose. The oxidative enzymes thought to be involved in lignin degradation by this model system include lignin peroxidases (LiP), manganese peroxidases (MnP), and the peroxide-generating enzyme glyoxal oxidase (GLOX). Recently, a draft P. chrysosporium genome sequence has been made publicly available (http://www.jgi.doe.gov/programs/whiterot.htm). Blast searches of this database unexpectedly revealed at least five additional GLOX-like sequences. Transcripts were detected in various defined culture media and from P. chrysosporium-colonized wood. Full length cDNAs were cloned and sequenced. Comparisons of these sequences to GLOX and to related Cu-related oxidases showed close structural similarities around the active site. Interestingly, three highly conserved CRO sequences are located within a LiP gene cluster. Designated cro3, cro4, and cro5, all three feature a conserved N-terminal putative carbohydrate binding domain. Active enzyme corresponding to cro3 has been produced in Aspergillus nidulans under the control of the A. niger glucoamylase promoter. Substrate specificity of the cro3 protein is under investigation.
Fungal Genet. Newsl. 50 (Supl):abstract
Full conference title:
22nd Fungal Genetics Conference
- Fungal Genetics Conference 22nd (2001)