The research team compared the 34-million-nucleotide genome of T. reesei with 13 previously characterized fungi and discovered something counterintuitive. Despite its reputation as an avid plant polysaccharide degrader, T. reesei, was found to have the smallest inventory of genes powering its robust degradation machinery.
We were aware of T. reeseis reputation as a producer of massive quantities of degrading enzymes, however we were surprised by how few enzyme types it produces, which suggested to us that its protein secretion system is exceptionally efficient, said Diego Martinez, the studys lead author and researcher supported by DOE JGI at LANL, and at the University of New Mexico. Subsequently, he and his colleagues turned their attention to the complexities of T. reeseis secretory pathway components, which they had a hunch played an important role in the organisms success.
While little appears to have changed in the secretion machinery since divergence with a common ancestor with yeast, said Martinez, there are some intriguing differences in the way T. reesei processes some protein bonds important for cellulase production.
In their comparative analysis of T. reesei with other fungi, the team observed clustering of carbohydrate-active enzyme genes, which suggested a specific biological role: polysaccharide degradation. While plant tissues are not likely the main source of nutrients for T. reesei, upon detection of cellulose and hemicellulose it seems that the organ
|Contact: David Gilbert|
DOE/Joint Genome Institute