Cloned (Comment) | Organism |
---|---|
gene chiA, cloning of wild-type and mutant enzymes in Escherichia coli strain DH5alpha, heterologous expression in Pichia pastoris strain X-33 | Zea mays |
Crystallization (Comment) | Organism |
---|---|
purified recombinant wild-type and mutant E64Q enzymes, sitting drop vapour diffusion method, mixing of 26 mg/ml protein in sodium acetate buffer, pH 5.2, with reservoir solution, X-ray diffraction structure determination and analysis | Zea mays |
Protein Variants | Comment | Organism |
---|---|---|
E62Q | site-directed mutagenesis of wild-type enzyme and mutant ChitA DELTAN, the mutation abolishes the chitinase activity of both full-length and truncated proteins without disrupting substrate binding | Zea mays |
additional information | construction of a truncated enzyme mutant, ChitA DELTAN, which lacks the hevein-like domain. The mutant enzyme activity is comparable to the wild-type full-length enzyme | Zea mays |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
28000 | - |
x * 28000 | Zea mays |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
chitin + H2O | Zea mays | - |
? | - |
? | |
chitin + H2O | Zea mays LH82 | - |
? | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Zea mays | P29022 | gene CHIA | - |
Zea mays LH82 | P29022 | gene CHIA | - |
Purification (Comment) | Organism |
---|---|
recombinant wild-type and mutant enzymes from Pichia pastoris strain X-33 by ammonium sulfate fractionation, cation exchange chromatography, and dialysis | Zea mays |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
seed | - |
Zea mays | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
chitin + H2O | - |
Zea mays | ? | - |
? | |
chitin + H2O | - |
Zea mays LH82 | ? | - |
? | |
additional information | enzyme activity on the modified chitopentaose substrate GlcN-GlcNAc4, which contains a non-acetylated glucosamine residue at the nonreducing end, and on the modified chitotetraose substrate TMG-chitotriomycin-pMP, which contains a N-trimethylamino glucosamine (TMG) residue at the non-reducing end, and a p-methyoxyphenyl protecting group at the anomeric position, cleavage product is TMG-GlcNAc2, MALDI-TOF mass spectrometry, overview | Zea mays | ? | - |
? | |
additional information | enzyme activity on the modified chitopentaose substrate GlcN-GlcNAc4, which contains a non-acetylated glucosamine residue at the nonreducing end, and on the modified chitotetraose substrate TMG-chitotriomycin-pMP, which contains a N-trimethylamino glucosamine (TMG) residue at the non-reducing end, and a p-methyoxyphenyl protecting group at the anomeric position, cleavage product is TMG-GlcNAc2, MALDI-TOF mass spectrometry, overview | Zea mays LH82 | ? | - |
? | |
p-methoxyphenyl TMG-chitotriomycin + H2O | a synthetic compound and an enzyme inhibitor specific for insect and fungal b-N-acetylglucosaminidases | Zea mays | ? | - |
? | |
p-methoxyphenyl TMG-chitotriomycin + H2O | a synthetic compound and an enzyme inhibitor specific for insect and fungal b-N-acetylglucosaminidases | Zea mays LH82 | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | x * 28000 | Zea mays |
Synonyms | Comment | Organism |
---|---|---|
ChitA | - |
Zea mays |
class IV chitinase | - |
Zea mays |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Zea mays |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5 | - |
assay at | Zea mays |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme is a glycoside hydrolase family 19 plant class IV chitinase. Family GH19 chitinases operate by an inverting glycoside mechanism. Comparison of the crystal structure of this plant class IV chitinase with structures from larger class I and II enzymes suggest that class IV chitinases have evolved to accommodate shorter substrates | Zea mays |
additional information | key roles for Glu62, Arg177, and Glu165 in hydrolysis, and for Ser103 and Tyr106 in substrate binding. Glu62 is directly involved in catalysis, while the hevein-like domain is not needed for enzyme activity. Proton donor and general base are Glu62 and Glu71, respectively. The catalytic triad highly conserved in GH19 chitinases, is composed of Glu62, Arg177, and Glu165 | Zea mays |
physiological function | the enzyme has in vitro antifungal activity in healthy maize seeds | Zea mays |