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Literature summary for 1.1.1.37 extracted from

  • Richard, S.B.; Madern, D.; Garcin, E.; Zaccai, G.
    Halophilic adaptation: novel solvent protein interactions observed in the 2.9 and 2.6 A resolution structures of the wild type and a mutant of malate dehydrogenase from Haloarcula marismortui (2000), Biochemistry, 39, 992-1000.
    View publication on PubMed
Search for more literature for 1.1.1.37

Cloned(Commentary)

Cloned (Comment) Organism
wild-type and E267R protein are overexpressed in Escherichia coli Haloarcula marismortui

Crystallization (Commentary)

Crystallization (Comment) Organism
the structure of the mutant E267R apoenzyme is determined to 2.6 A resolution and the structure of the wild-type apoenzyme is determined to 2.9 A resolution Haloarcula marismortui

Protein Variants

Protein Variants Comment Organism
E267R the numbering is not equivalent to the numbering of UniProt. The E267R mutation points into a central ordered water cavity, disrupting protein-solvent interactions. The mutant enzyme requires higher concentrations of the solvent salt for stability similar to that of the wild type Haloarcula marismortui
R207S/R292S the numbering is not equivalent to the numbering of UniProt. The active tetrameric mutant enzyme R207S/R292S dissociates under certain conditions to active dimers and under other conditions to inactive dimers. These dimers further dissociate into folded monomers which eventually unfold. The mutant enzyme requires higher salt concentrations than the wild type for stability. Thermal inactivation starts at 35°C, whereas the wild type is stable up to 60°C. At 4 M NaCl (pH 8) the kinetics of unfolding of the mutant is measured by following the fluorescence emission during incubation at various temperatures. The process is biphasic between 35 and 48 °C, while the thermal deactivation kinetics of the wild type protein is first-order Haloarcula marismortui

Organism

Organism UniProt Comment Textmining
Haloarcula marismortui Q07841
-
-
Haloarcula marismortui DSM 3752 Q07841
-
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
oxaloacetate + NADH + H+
-
 Haloarcula marismortui (S)-malate + NAD+
-
 ?
oxaloacetate + NADH + H+
-
 Haloarcula marismortui DSM 3752 (S)-malate + NAD+
-
 ?

Subunits

Subunits Comment Organism
dimer in the wild type the dimeric enzyme form is very unstable under low-salt conditions. The R207S/R292S mutation stabilizes the dimer sufficiently so that it can be observed and studied. The R207S/R292S mutant enzyme dissociates into dimers at 2 M NaCl, or at very low protein concentrations in 4 M NaCl above pH 7. This dimer is as active as the wild type tetramer at pH 8 but loses its activity at pH 7, without large changes in structure or association state Haloarcula marismortui
monomer the monomer is in an inactive molten globule-like state, which can be reactivated through a structural change induced by NADH binding that allows it to associate into active dimers Haloarcula marismortui
tetramer stabilized by ordered water molecule networks and intersubunit complex salt bridges locked in by bound solvent chloride and sodium ions Haloarcula marismortui
tetramer the active tetrameric mutant enzyme R207S/R292S dissociates under certain conditions to active dimers and under other conditions to inactive dimers. These dimers further dissociate into folded monomers which eventually unfold. In 4 M NaCl (pH 8) and for the protein concentration range above 5 mg/ml, the R207S/R292S mutant enzyme is predominantly a tetramer Haloarcula marismortui

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
25
-
 assay at Haloarcula marismortui

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
45
-
 30 min, 50% loss of activity, mutant enzyme R207S/R292S Haloarcula marismortui
75
-
 30 min, 50% loss of activity, wild-type enzyme Haloarcula marismortui

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
8
-
 assay at Haloarcula marismortui