4.1.2.48: low-specificity L-threonine aldolase
This is an abbreviated version!
For detailed information about low-specificity L-threonine aldolase, go to the full flat file.
Word Map on EC 4.1.2.48
Reaction
Synonyms
GLY1, GlyA, L-TA, L-threonine aldolase, low specificity L-TA, low specificity threonine aldolase, Low-specificity L-threonine aldolase, LTA, LtaE, serine hydroxy-methyl transferase, SHMT, threonine aldolase
ECTree
4.1.2.48 low-specificity L-threonine aldolaseAdvanced search results
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results (Engineering
Engineering on EC 4.1.2.48 - low-specificity L-threonine aldolase
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PROTEIN VARIANTS 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
F87A
F87D
H126F
-
300% of wild-type activity,reduced preference for the erythro-substrate
H83F
-
less than 1% of wild-type activity, reduced preference for the erythro-substrate
H83F/H126F
industry
biocatalysis using threonine aldolases opens up a way to synthesise beta-hydroxy-alpha-amino acids in one step. Dichiral beta-hydroxy-alpha-amino acids are a highly valuable class of compounds from which pharmaceutically active intermediates for the synthesis of e.g. beta-sympathomimetic drugs. Methods to immobilise the L-low specificity threonine aldolase of Escherichia coli are studied. The entrapment of the enzyme into a porous network of orthosilicate appears to be the most promising method
K222A
synthesis
biocatalysis using threonine aldolases opens up a way to synthesise beta-hydroxy-alpha-amino acids in one step. Dichiral beta-hydroxy-alpha-amino acids are a highly valuable class of compounds from which pharmaceutically active intermediates for the synthesis of e.g. beta-sympathomimetic drugs. Methods to immobilise the L-low specificity threonine aldolase of Escherichia coli are studied. The entrapment of the enzyme into a porous network of orthosilicate appears to be the most promising method
F87A
-
no change in the ration of cleavage of L-threonine to L-allo-threonine
-
F87D
-
mutation doubles the preference of the enzyme for L-allo-threonine
-
H126F
-
300% of wild-type activity,reduced preference for the erythro-substrate
-
K222A
-
slight decrease in kcat and slight increase in Km values for both L-threonine and L-allo-threonine
-
K207A
the mutant enzyme shows no detectable enzyme activity. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
K207R
the mutant enzyme shows a specific activity of about 1000 times lower than that of the wild-type enzyme. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
K207A
-
the mutant enzyme shows no detectable enzyme activity. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
-
K207R
-
the mutant enzyme shows a specific activity of about 1000 times lower than that of the wild-type enzyme. The mutant enzyme show the disappearance of the absorption maximum at 420 nm, indicating that the Schiff base linkage between the epsilon-amino group of the active-site lysine residue and the pyridoxal 5'-phosphate cofactor aldehyde group of the wild type is not present in the mutant enzyme
-
F18I
-
stability-enhanced mutant, half life at 63°C is 5.0 min, the specific activity is decreased by 45% compared to the wild type enzyme
R241C/A287V
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
V86I/R241C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y34C
-
the mutation dramatically increases the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C/A48T
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
Y39C/Y306C/R316C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
F18I
-
stability-enhanced mutant, half life at 63°C is 5.0 min, the specific activity is decreased by 45% compared to the wild type enzyme
-
R241C/A287V
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
V86I/R241C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
Y34C
-
the mutation dramatically increases the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
Y39C/Y306C
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
Y39C/Y306C/A48T
-
the mutations dramatically increase the diastereoselectivity of the reverse aldol condensation activity for L-threo-3,4-dihydroxyphenylserine
-
F87A
-
no change in the ration of cleavage of L-threonine to L-allo-threonine
F87A
catalytic efficiency of the mutant enzyme for L-threonine is 1.7fold lower than that of the wild-type enzyme, catalytic efficiency of the mutant enzyme for L-allo-threonine is 1.2fold lower than that of the wild-type enzyme
F87D
catalytic efficiency of the mutant enzyme for L-threonine is 3.11fold lower than that of the wild-type enzyme, catalytic efficiency of the mutant enzyme for L-allo-threonine is 7.5fold lower than that of the wild-type enzyme
H83F/H126F
-
able to catalyze the cleavage of both L-threonine and L-allo-threonine at a measurable rate, neither of the histidines acts as a catalytic base in the retro-aldol cleavage mechanism
H83F/H126F
catalytic efficiency of the mutant enzyme for L-threonine is 3890fold lower than that of the wild-type enzyme, catalytic efficiency of the mutant enzyme for L-allo-threonine is 294fold lower than that of the wild-type enzyme
K222A
-
slight decrease in kcat and slight increase in Km values for both L-threonine and L-allo-threonine
K222A
catalytic efficiency of the mutant enzyme for L-threonine is 13.4fold lower than that of the wild-type enzyme, catalytic efficiency of the mutant enzyme for L-allo-threonine is 9.7fold lower than that of the wild-type enzyme
