Cloned (Comment) | Organism |
---|---|
gene XTH15, recombinant expression in Pichia pastoris | Arabidopsis thaliana |
gene XTH31, recombinant expression in Pichia pastoris | Arabidopsis thaliana |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | kinetics of 1.6 mg/ml with xyloglucan, xyloglucan endotransglucosylase activity. Comparisons of kinetics of isozyme XTH15 and XTH31 from Arabidopsis thaliana, overview | Arabidopsis thaliana | |
additional information | - |
additional information | kinetics of 2.9 mg/ml with xyloglucan, xyloglucan endotransglucosylase activity. Comparisons of kinetics of isozyme XTH15 and XTH31 from Arabidopsis thaliana, overview | Arabidopsis thaliana | |
0.031 | - |
XXXGol | xyloglucan endotransglucosylase activity, pH 5.5, 20°C | Arabidopsis thaliana | |
0.0386 | - |
XXXG-ol | xyloglucan endotransglucosylase activity, pH 5.5, 20°C | Arabidopsis thaliana |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | P93046 | gene XTH31 | - |
Arabidopsis thaliana | Q38911 | gene XTH15 | - |
no activity in Pichia pastoris | - |
- |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
additional information | isozyme XTH15 is predominantly expressed in early-stage organs | Arabidopsis thaliana | - |
additional information | isozyme XTH31 is predominantly expressed in early-stage organs | Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | isozyme XHT31 shows predominant undetectable xyloglucan endohydrolase, XEH, activity and has only slight xyloglucan endotransglucosylase, XET, activity in vitro. Usage of XXXG-ol as acceptor substrate and of xyloglucan as donor substrate. XXXG-ol is the preferred XET acceptor substrate, among five cellotetraitol-based oligosaccharides tested. Isozyme XTH31's XET activity is strongly compromised when the second Xyl residue is galactosylated. XTH31 cleaves the substrate from about 186 kDa to 6 kDa (median sizes) within 40 h, gas spectrometric analysis. The isozyme does not have a preferred cleavage site close to either terminus. The complete hydrolysis of a 186-kDa tamarind xyloglucan molecule to yield Glc4-based oligosaccharides would require about 150 cuts. XEH action continues for at least 40 h, with an initial rate of about 1.5 cuts per starting molecule per hour. Substrate specificity of Arabidopsis thaliana XET isozymes XTH15 and XTH31, overview. The acceptor site of XTH31 is relatively poor at accommodating substrates that have Gal (or Fuc-Gal) simultaneously on the 2nd and 3rd isoprimeverose groups, counted from the nonreducing end | Arabidopsis thaliana | ? | - |
? | |
additional information | isozyme XTH15 has high xyloglucan endotransglucosylase, XET, and undetectable xyloglucan endohydrolase, XEH, activity in vitro. Usage of XXXG-ol as acceptor substrate and of xyloglucan as donor substrate. XXXG-ol is the preferred XET acceptor substrate, among five cellotetraitol-based oligosaccharides tested. XTH15's XET activity tolerateds substitution at the second Xyl residue. Substrate specificity of Arabidopsis thaliana XET isozymes XTH15 and XTH31, overview | Arabidopsis thaliana | ? | - |
? | |
XXXG-ol + xyloglucan | - |
Arabidopsis thaliana | ? | - |
? | |
XXXGol + xyloglucan | - |
Arabidopsis thaliana | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
XET | - |
Arabidopsis thaliana |
XTH | - |
Arabidopsis thaliana |
XTH15 | - |
Arabidopsis thaliana |
XTH31 | - |
Arabidopsis thaliana |
xyloglucan endotransglucosylase/hydrolase | - |
Arabidopsis thaliana |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
20 | - |
assay at | Arabidopsis thaliana |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5 | - |
- |
Arabidopsis thaliana |
6 | - |
isozyme XTH15 exhibits an unusually broad pH optimum, inactive at pH 3.5 and below, xyloglucan endotransglucosylase activity | Arabidopsis thaliana |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
isozyme XTH31's hydrolase activity increases almost linearly with decreasing pH in the apoplastic range, pH6.2-4.5, consistent with a possible role in acid growth, inactive at pH 3.5 and below, xyloglucan endotransglucosylase activity | Arabidopsis thaliana |
Organism | Comment | Expression |
---|---|---|
Arabidopsis thaliana | the isozyme is repressed by aluminium, Al3+ | down |
General Information | Comment | Organism |
---|---|---|
evolution | xyloglucan endotransglucosylase/hydrolases (XTHs) are encoded in Arabidopsis by a 33-member gene family, isozyme XTH15 is a classical group-I/II XTH | Arabidopsis thaliana |
evolution | xyloglucan endotransglucosylase/hydrolases (XTHs) are encoded in Arabidopsis by a 33-member gene family, isozyme XTH31 is a group-III-A XTH | Arabidopsis thaliana |
malfunction | mutant seedlings defective in XTH15 exhibit no visible growth defects possibly because isozyme XTH16 closely resembles XTH15 in sequence, pI and expression profile | Arabidopsis thaliana |
physiological function | isozyme XTH15 is predominantly expressed in early-stage organs, and thus seem likely to participate in cell expansion | Arabidopsis thaliana |
physiological function | isozyme XTH31 is predominantly expressed in early-stage organs, and thus seem likely to participate in cell expansion. XTH31 is responsible for a specific mode of cell elongation that is particularly Al3+-sensitive. In the wild-type, a second mode of cell expansion that is more Al3+-resistant must be occurring simultaneously | Arabidopsis thaliana |