Cloned (Comment) | Organism |
---|---|
gene xyl1, recombinant expression of the enzyme in Synechococcus elongatus strain PCC7942, functional co-expression with a xylose transporter from Escherichia coli, Ec-XylE | [Candida] boidinii |
Protein Variants | Comment | Organism |
---|---|---|
additional information | efficient uptake and reduction of xylose photoautotrophically in Synechococcus elongatus strain PCC7942 are demonstrated upon introduction of an effective xylose transporter from Escherichia coli (Ec-XylE) and the NADPH-dependent xylose reductase from Candida boidinii (Cb-XR). Simultaneous activation of xylose uptake and matching of cofactor specificity enables an average xylitol yield of 0.9 g/g xylose and a maximum productivity of about 0.15 g/l/day/OD with increased level of xylose supply. High-density conversion of xylose to xylitol using concentrated resting cells further pushes the titer of xylitol formation to 33 g/l in six days with 85% of maximum theoretical yield. Comparison of the efficiencies of the two routes for xylitol biosynthesis, detailed overview | [Candida] boidinii |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | Michaelis-Menten kinetics | [Candida] boidinii |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-xylose + NADPH + H+ | [Candida] boidinii | - |
xylitol + NADP+ | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
[Candida] boidinii | Q8X195 | - |
- |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
enzyme activities in different engineered Synechococcus elongatus strain PCC7942 variants, overview | [Candida] boidinii |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-xylose + NADPH + H+ | - |
[Candida] boidinii | xylitol + NADP+ | - |
r |
Synonyms | Comment | Organism |
---|---|---|
Cb-XR | - |
[Candida] boidinii |
NADPH-dependent xylose reductase | - |
[Candida] boidinii |
XYL1 | - |
[Candida] boidinii |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
in vivo assay at | [Candida] boidinii |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | [Candida] boidinii |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADP+ | - |
[Candida] boidinii | |
NADPH | - |
[Candida] boidinii |
General Information | Comment | Organism |
---|---|---|
metabolism | biosynthesis of xylitol can be achieved from two distinctive routes, one occurs via the activity of NADPH-dependent xylose reductase (XR), reducing xylose directly into xylitol. The other one proceeds via formation of the intermediate xylulose through xylose isomerase (XI, EC 5.3.1.5) followed by NADH-dependent reduction via the xylitol dehydrogenase (XDH, EC 1.1.1.9). Both of the metabolic routes originate from xylose dissimilation and can lead to formation of xylulose-5-phosphtate, the entrance point of pentose phosphate pathway | [Candida] boidinii |