Activating Compound | Comment | Organism | Structure |
---|---|---|---|
dithiothreitol | - |
Hordeum vulgare | |
dithiothreitol | 150% activity at 2 mM | Hordeum vulgare |
Cloned (Comment) | Organism |
---|---|
isoform UXE1 is expressed in Pichia pastoris | Hordeum vulgare |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | UMP and EDTA do not inhibit the activity of the recombinant isoform UXE1 | Hordeum vulgare | |
UDP | 15% residual activity at 2 mM | Hordeum vulgare | |
UTP | 54% residual activity at 2 mM | Hordeum vulgare |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.4 | - |
UDP-beta-L-arabinopyranose | pH 7.0, at 25°C | Hordeum vulgare | |
1.8 | - |
UDP-alpha-D-xylopyranose | pH 7.0, at 25°C | Hordeum vulgare |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
additional information | Mg2+ does not stimulate the activity of the recombinant isoform UXE1. Addition of NADH or NAD+ has no significant effect on activity | Hordeum vulgare |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
45000 | - |
isoform UXE3, calculated from amino acid sequence | Hordeum vulgare |
47000 | - |
isoform UXE1, calculated from amino acid sequence | Hordeum vulgare |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Hordeum vulgare | Q2LC81 | isoform UXE3 | - |
Hordeum vulgare | Q2LC82 | isoform UXE2 | - |
Hordeum vulgare | Q2LC83 | isoform UXE1 | - |
Purification (Comment) | Organism |
---|---|
Ni-NTA column chromatography | Hordeum vulgare |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
endosperm | - |
Hordeum vulgare | - |
Storage Stability | Organism |
---|---|
4°C, purified enzyme, at least 1 week, little or no loss of activity | Hordeum vulgare |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | the purified recombinant isoform UXE1 does not catalyze the interconversion of UDP-glucose and UDP-galactose | Hordeum vulgare | ? | - |
? | |
UDP-alpha-D-xylopyranose | - |
Hordeum vulgare | UDP-beta-L-arabinopyranose | - |
r | |
UDP-beta-L-arabinopyranose | - |
Hordeum vulgare | UDP-alpha-D-xylopyranose | - |
r |
Synonyms | Comment | Organism |
---|---|---|
UDP-alpha-D-xylose 4-epimerase | - |
Hordeum vulgare |
UXE1 | isoform | Hordeum vulgare |
UXE2 | isoform | Hordeum vulgare |
UXE3 | isoform | Hordeum vulgare |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.5 | - |
UDP-beta-L-arabinopyranose | pH 7.0, at 25°C | Hordeum vulgare | |
1.5 | - |
UDP-alpha-D-xylopyranose | pH 7.0, at 25°C | Hordeum vulgare |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
about pH 7.0 | Hordeum vulgare |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NAD+ | - |
Hordeum vulgare | |
NAD+ | each molecule of isoform UXE1 contains about one molecule of noncovalently bound NAD+ | Hordeum vulgare |
Organism | Comment | Expression |
---|---|---|
Hordeum vulgare | isoform UXE2 transcript abundance is moderate during the syncytial stage of endosperm development (2-6 days after pollination) but decreases to undetectable levels beyond 6 days after pollination | down |
Hordeum vulgare | in developing barley endosperm, isoform UXE3 mRNA levels peak at a time when UDP-alpha-D-xylopyranose synthase transcripts also reach a maximum and when arabinoxylan biosynthesis is initiated | up |
Hordeum vulgare | in developing barley endosperm, isoforms UXE1 mRNA levels peak at a time when UDP-alpha-D-xylopyranose synthase transcripts also reach a maximum and when arabinoxylan biosynthesis is initiated. Transcript levels for the UXE1 gene are about 4fold higher at 9 days after pollination than in the syncytial and cellularization stages | up |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.9 | - |
UDP-alpha-D-xylopyranose | pH 7.0, at 25°C | Hordeum vulgare | |
1.1 | - |
UDP-beta-L-arabinopyranose | pH 7.0, at 25°C | Hordeum vulgare |