This is a efficient xylose utilization composite part.
This is an efficient xylose utilization BBa_K3803016 we built to achieve a functional improvement based on the parts BBa_K2314913 & BBa_K2314324 (Although they were uploaded as basic parts separately, they worked together as a composite part) from OUC_China in 2017 iGEM.
Xylose reductase (XR) will first transform xylose to xylitol, and xylitol dehydrogenase (XDH) can further convert xylitol to xylulose. Then, xylulose will be converted to xylulose 5-phosphate (X5P) by the native xylulose kinase (XK). Apart from the original XR and XDH genes, considering the low copy number of native XK gene in S. cerevisiae, we introduced an extra XK gene to improve the xylose utilization ability.
Xylose Utilization Ability: For Cell Growth
For cell growth, OUC_China achieved a final OD600 around 2.35 in YNB-based xylose media. After our improvement on their parts, we could get a final OD600 around 20.
Xylose Utilization Ability: For Production Yield
For our own product yield, our production also improved after substituting our three-gene cassette for OUC_China's two-gene one. The improved production was very obvious after the parts improvement based on our HPLC results.
For more information about our parts and improvement, you can also see details here
 Construction of efficient xylose-fermenting Saccharomyces cerevisiae through a synthetic isozyme system of xylose reductase from Scheffersomyces stipitis. Bioresource Technology, Jung-Hyun Jo, Yong-Cheol Park, Yong-Su Jin, Jin-Ho Seo, Bioresource Technology, 241 (2017) 88–94.
 Metabolic engineering of Saccharomyces cerevisiae for production of Shinorine, a sunscreen material, from xylose. Seong-Hee Park, Kyusung Lee, Jae Woo Jang and Ji-Sook Hahn, ACS Synthetic Biology, 2019 (8), 346−357.Sequence and Features