Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 1.1.1.3 extracted from

  • Ohshida, T.; Koba, K.; Hayashi, J.; Yoneda, K.; Ohmori, T.; Ohshima, T.; Sakuraba, H.
    A novel bifunctional aspartate kinase-homoserine dehydrogenase from the hyperthermophilic bacterium, Thermotoga maritima (2018), Biosci. Biotechnol. Biochem., 82, 2084-2093 .
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
gene TM_0547 , sequence comparisons, recombinant expression of the enzyme in Escherichia coli strain BL21(DE3) Thermotoga maritima

Inhibitors

Inhibitors Comment Organism Structure
additional information L-homoserine oxidation of the Thermotoga maritima enzyme is almost impervious to inhibition by L-threonine, while L-threonine inhibits AK activity in a cooperative manner. The distinctive sequence of the regulatory domain in Thermotoga maritima AK-HseDH is likely responsible for the unique sensitivity to L-threonine. The quaternary structure of this enzyme is not affected by L-threonine Thermotoga maritima

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.064
-
NADP+ recombinant enzyme, pH 10.5, 55°C Thermotoga maritima
1.81
-
L-homoserine recombinant enzyme, pH 10.5, 55°C Thermotoga maritima

Molecular Weight [Da]

Molecular Weight [Da] Molecular Weight Maximum [Da] Comment Organism
450000
-
about, recombinant enzyme, gel filtration Thermotoga maritima

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
L-homoserine + NADP+ Thermotoga maritima
-
L-aspartate 4-semialdehyde + NADPH + H+
-
?
L-homoserine + NADP+ Thermotoga maritima DSM 3109
-
L-aspartate 4-semialdehyde + NADPH + H+
-
?
L-homoserine + NADP+ Thermotoga maritima ATCC 43589
-
L-aspartate 4-semialdehyde + NADPH + H+
-
?
L-homoserine + NADP+ Thermotoga maritima JCM 10099
-
L-aspartate 4-semialdehyde + NADPH + H+
-
?

Organism

Organism UniProt Comment Textmining
Thermotoga maritima Q9WZ17
-
-
Thermotoga maritima ATCC 43589 Q9WZ17
-
-
Thermotoga maritima DSM 3109 Q9WZ17
-
-
Thermotoga maritima JCM 10099 Q9WZ17
-
-

Purification (Commentary)

Purification (Comment) Organism
recombinant enzyme from Escherichia coli strain BL21(DE3) by heat treatment, hydrophobic interaction chromatography, gel filtration, hydroxyapatite chromatography, and ultrafiltration Thermotoga maritima

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
66.5
-
purified recombinant enzyme, pH 10.5, 55°C Thermotoga maritima

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
L-homoserine + NADP+
-
Thermotoga maritima L-aspartate 4-semialdehyde + NADPH + H+
-
?
L-homoserine + NADP+
-
Thermotoga maritima DSM 3109 L-aspartate 4-semialdehyde + NADPH + H+
-
?
L-homoserine + NADP+
-
Thermotoga maritima ATCC 43589 L-aspartate 4-semialdehyde + NADPH + H+
-
?
L-homoserine + NADP+
-
Thermotoga maritima JCM 10099 L-aspartate 4-semialdehyde + NADPH + H+
-
?
additional information the bifunctional enzyme also exhibits aspartokinase (AK) activity, EC 2.7.2.4. It shows substantial activities of both AK and homoserine dehydrogenase (HseDH) Thermotoga maritima ?
-
-
additional information the bifunctional enzyme also exhibits aspartokinase (AK) activity, EC 2.7.2.4. It shows substantial activities of both AK and homoserine dehydrogenase (HseDH) Thermotoga maritima DSM 3109 ?
-
-
additional information the bifunctional enzyme also exhibits aspartokinase (AK) activity, EC 2.7.2.4. It shows substantial activities of both AK and homoserine dehydrogenase (HseDH) Thermotoga maritima ATCC 43589 ?
-
-
additional information the bifunctional enzyme also exhibits aspartokinase (AK) activity, EC 2.7.2.4. It shows substantial activities of both AK and homoserine dehydrogenase (HseDH) Thermotoga maritima JCM 10099 ?
-
-

Subunits

Subunits Comment Organism
homopentamer or homohexamer x * 81000, recombinant enzyme, SDS-PAGE, x * 81433, sequence calculation Thermotoga maritima

Synonyms

Synonyms Comment Organism
AK-HseDH
-
Thermotoga maritima
bifunctional aspartate kinase-homoserine dehydrogenase
-
Thermotoga maritima
HseDH
-
Thermotoga maritima
More see also EC 2.7.2.4 Thermotoga maritima
TM_0547
-
Thermotoga maritima

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
70
-
Hse oxidation Thermotoga maritima

Temperature Range [°C]

Temperature Minimum [°C] Temperature Maximum [°C] Comment Organism
50 80 over 30% of maximal activity within this range, profile overview Thermotoga maritima

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
50 100 purified recombinant enzyme, 10 min, completely stable at 50-90°C, loss of 40% activity at 100°C Thermotoga maritima

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
10.5
-
Hse oxidation Thermotoga maritima

pH Range

pH Minimum pH Maximum Comment Organism
6.5 11 over 60% of maximal activity within this range, profile overview Thermotoga maritima

pH Stability

pH Stability pH Stability Maximum Comment Organism
5 12 purified recombinant enzyme, 10 min, 50°C, completely stable at pH 5.5-10.5, loss of 25% activity at pH 11.0, loss of 70% activity at pH 5.0 and pH 11.5, inactivation at pH 12.0 Thermotoga maritima

Cofactor

Cofactor Comment Organism Structure
NADP+
-
Thermotoga maritima
NADPH
-
Thermotoga maritima

General Information

General Information Comment Organism
evolution the orientation of the three domains in the bifunctional aspartate kinase-homoserine dehydrogenase (AK-HseDH) homologue found in Thermotoga maritima totally differs from those observed in previously known AK-HseDHs, the domains line up in the order HseDH, AK, and regulatory domain Thermotoga maritima
metabolism biosynthetic pathway from L-aspartate to L-homoserine involving the bifunctional enzyme, overview Thermotoga maritima
physiological function aspartate kinase (AK, EC 2.7.2.4) and homoserine dehydrogenase (HseDH) are involved in the biosynthetic pathway from L-aspartate to L-homoserine (Hse) in plants and microorganisms. Hse is a common precursor for the synthesis of L-methionine, L-threonine, and L-isoleucine. At the first step in this pathway, L-aspartate is phosphorylated to beta-aspartyl phosphate (beta-Ap) by AK Thermotoga maritima