Cloned (Comment) | Organism |
---|---|
gene lacB, construction of a genomic library, DNA and amino acid sequence determination and anaylsis, expression as GST-tagged enzyme in Escherichia coli strain BL21RB791 | Alicyclobacillus acidocaldarius |
Protein Variants | Comment | Organism |
---|---|---|
E157G | site-directed mutagenesis, altered kinetics compared to the wild-type enzyme | Alicyclobacillus acidocaldarius |
E313G | site-directed mutagenesis, altered kinetics compared to the wild-type enzyme | Alicyclobacillus acidocaldarius |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.11 | - |
2-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, mutant E157G | Alicyclobacillus acidocaldarius | |
4.8 | - |
2-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, mutant E313G | Alicyclobacillus acidocaldarius | |
4.9 | - |
4-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
5.2 | - |
4-nitrophenyl-alpha-L-arabinopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
5.5 | - |
2-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
7.3 | - |
2-nitrophenyl-beta-D-fucopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
18.2 | - |
lactulose | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
60.8 | - |
lactose | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cytosol | - |
Alicyclobacillus acidocaldarius | 5829 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
additional information | the enzyme is not affected by 5 mM of Mg2+, Mn2+, or Ca2+ | Alicyclobacillus acidocaldarius |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Alicyclobacillus acidocaldarius | Q0R5R5 | subsp. rittmanii, a thermoacidophilic bacterium, strain ATCC 27009 | - |
Purification (Comment) | Organism |
---|---|
native enzyme 46fold by anion exchange and hydrophobic interaction chromatography and gel filtration, recombinant GST-tagged enzyme from Escherichia coli strain BL21RB791 by heat treatment at 60°C and hydrophobic interaction chromatography to over 95% purity | Alicyclobacillus acidocaldarius |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
beta-D-galactopyranosyl-(1-4)-beta-D-galactopyranosyl-(1-6)-beta-D-galactopyranosyl-(1-3)-beta-D-galactopyranose + 3 H2O = 4 beta-D-galactopyranose | catalytic mechanism, active site structure,Glu157 acts as the acid/base in the catalytic reaction | Alicyclobacillus acidocaldarius |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
additional information | optimal growth pH is pH 4.0 | Alicyclobacillus acidocaldarius | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
- |
Alicyclobacillus acidocaldarius |
592 | - |
purified native enzyme | Alicyclobacillus acidocaldarius |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2-nitrophenyl beta-D-galactopyranoside + H2O | - |
Alicyclobacillus acidocaldarius | 2-nitrophenol + beta-D-galactose | - |
? | |
2-nitrophenyl-beta-D-fucopyranoside + H2O | - |
Alicyclobacillus acidocaldarius | 2-nitrophenol + beta-D-fucose | - |
? | |
4-nitrophenyl beta-D-galactopyranoside + H2O | - |
Alicyclobacillus acidocaldarius | 4-nitrophenol + beta-D-galactose | - |
? | |
4-nitrophenyl-alpha-L-arabinopyranoside + H2O | - |
Alicyclobacillus acidocaldarius | 4-nitrophenol + alpha-L-arabinose | - |
? | |
lactose + H2O | - |
Alicyclobacillus acidocaldarius | D-glucose + D-galactose | - |
? | |
lactulose + H2O | - |
Alicyclobacillus acidocaldarius | D-fructose + D-galactose | - |
? | |
additional information | the enzyme is very specific for glycosides with an axial C4-OH at their non-reducing end, no activity with cellobiose, glucosides, or xylosides | Alicyclobacillus acidocaldarius | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
Aabeta-gal | - |
Alicyclobacillus acidocaldarius |
More | the enzyme belongs to the glycosyl hydrolase family 42 | Alicyclobacillus acidocaldarius |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
65 | 70 | assay at | Alicyclobacillus acidocaldarius |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
35 | 85 | - |
Alicyclobacillus acidocaldarius |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
65 | - |
3 h, 90% remianing activity | Alicyclobacillus acidocaldarius |
80 | - |
half-life 6 min | Alicyclobacillus acidocaldarius |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.21 | - |
2-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, mutant E313G | Alicyclobacillus acidocaldarius | |
0.32 | - |
2-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, mutant E157G | Alicyclobacillus acidocaldarius | |
212 | - |
lactose | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
380 | - |
lactulose | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
1345 | - |
2-nitrophenyl-beta-D-fucopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
1740 | - |
4-nitrophenyl-alpha-L-arabinopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
2657 | - |
2-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius | |
2988 | - |
4-nitrophenyl-beta-D-galactopyranoside | pH 6.5, 65°C, wild-type enzyme | Alicyclobacillus acidocaldarius |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5.5 | 6.5 | assay at | Alicyclobacillus acidocaldarius |