Requires pyridoxal phosphate. The low-specificity L-threonine aldolase can act on both L-threonine and L-allo-threonine [1,2]. The enzyme from Escherichia coli can also act on L-threo-phenylserine and L-erythro-phenylserine . The enzyme can also catalyse the aldol condensation of glycolaldehyde and glycine to form 4-hydroxy-L-threonine, an intermediate of pyridoxal phosphate biosynthesis . Different from EC 4.1.2.5, L-threonine aldolase, and EC 4.1.2.49, L-allo-threonine aldolase.
Requires pyridoxal phosphate. The low-specificity L-threonine aldolase can act on both L-threonine and L-allo-threonine [1,2]. The enzyme from Escherichia coli can also act on L-threo-phenylserine and L-erythro-phenylserine [4]. The enzyme can also catalyse the aldol condensation of glycolaldehyde and glycine to form 4-hydroxy-L-threonine, an intermediate of pyridoxal phosphate biosynthesis [3]. Different from EC 4.1.2.5, L-threonine aldolase, and EC 4.1.2.49, L-allo-threonine aldolase.
low-specificity L-threonine aldolase is involved in a serendipitous pathway that converts 3-phosphohydroxypyruvate, an intermediate in the serine biosynthesis pathway, to L-4-phosphohydroxythreonine, an intermediate in the pyridoxal-5'-phosphate synthesis pathway in a strain of Escherichia coli that lacks 4-phosphoerythronate dehydrogenase
low-specificity L-threonine aldolase is involved in a serendipitous pathway that converts 3-phosphohydroxypyruvate, an intermediate in the serine biosynthesis pathway, to L-4-phosphohydroxythreonine, an intermediate in the pyridoxal-5'-phosphate synthesis pathway in a strain of Escherichia coli that lacks 4-phosphoerythronate dehydrogenase
knockout of the ltaE gene of wild-type Escherichia coli does not affect the cellular growth rate, while disruption of the ltaE gene of Escherichia coli GS245, whose serine hydroxymethyltransferase gene is knocked out, causes a significant decrease in the cellular growth rate, suggesting that the threonine aldolase is not a major source of cellular glycine in wild-type Escherichia coli but catalyzes an alternative pathway for cellular glycine when serine hydroxymethyltransferase is inert
threonine aldolase is not a major source of cellular glycine in wild-type Escherichia coli but catalyzes an alternative pathway for cellular glycine when serine hydroxymethyltransferase is inert
low-specificity L-threonine aldolase is involved in a serendipitous pathway that converts 3-phosphohydroxypyruvate, an intermediate in the serine biosynthesis pathway, to L-4-phosphohydroxythreonine, an intermediate in the pyridoxal-5'-phosphate synthesis pathway in a strain of Escherichia coli that lacks 4-phosphoerythronate dehydrogenase
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
the crystal structure of the low-specificity L-threonine aldolase is determined at 2.2 A resolution, in the unliganded form and co-crystallized with L-serine and L-threonine
at 2.2 A resolution, in the unliganded form and cocrystallized with L-serine and L-threonine. No active site catalytic residue is revealed, and a structural water molecule is assumed to act as the catalytic base in the retro-aldol cleavage reaction. The very large active site opening suggests that much larger molecules than L-threonine isomers may be easily accommodated
hanging drop vapor diffusion, low-pH crystal structure of the enzyme at 2.1 A resolution, with a noncovalently bound uncleaved L-serine substrate, and a pyridoxal 5'-phosphate cofactor bound as an internal aldimine. This structure contrasts with other Escherichia coli L-threonine aldolase structures obtained at physiological pH that show products or substrates bound as pyridoxal 5'-phosphate-external aldimines. The non-productive binding at low-pH is due to an unusual substrate serine binding orientation in which the alpha-amino group and carboxylate group are in the wrong positions (relative to the active site residues) as a result of protonation of the alpha-amino group of the serine, as well as the active site histidines, His83 and His126. Protonation of these residues prevent the characteristic nucleophilic attack of the alpha-amino group of substrate serine on C4' of pyridoxal 5'-phosphate to form the external aldimine. At low pH the change in charge distribution at the active site can result in substrates binding in a non-productive orientation
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
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
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
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
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
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
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
the enzyme may be exploited for bioorganic synthesis of L-3-hydroxyamino acids that are biologically active or constitute building blocks for pharmaceutical molecules
synthesis of optically active beta-hydroxy-alpha-amino acids by immobilized Escherichia coli cells expressing the enzyme. The immobilized cells can be continuously used 10 times, yielding an average conversion rate of 60.4%
Serine hydroxymethyl transferase from Streptococcus thermophilus and L-threonine aldolase from Escherichia coli as stereocomplementary biocatalysts for the synthesis of beta-hydroxy-alpha,omega-diamino acid derivatives