Pls help me with this plasmid!!! - (Apr/24/2012 )

I've been finding some inform about this plasmid for the production of monoclonal antibodies (anti-HER2 mab for breast cancer) by glycoengineered Pichia pastoris. However, there are some limitation in searching the function of "TRP2 gene", 1 article said this gene is P. pastoris TRP2 gene or transcription unit. I dont know why we need this gene for the vector. Anyone pls help me with this, thank you in advance!

oh, what a relieve! I finally got the answer when looking at an article of METHOD FOR PREPARING ANTIBODIES HAVING IMPROVED PROPERTIES It said the gene function is nonsense , interesting right! What makes sense here is the restriction site spel in this gene. The Genomic insertion into Pichia pastoris can be achieved by linearization of the vector with Spel and targeted integration into the Trp2 site!!!