 |
PDBsum entry 2d4a
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Oxidoreductase
|
PDB id
|
|
|
|
2d4a
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Refolding, Characterization and crystal structure of (s)-Malate dehydrogenase from the hyperthermophilic archaeon aeropyrum pernix.
|
|
|
Authors
|
|
R.Kawakami,
H.Sakuraba,
S.Goda,
H.Tsuge,
T.Ohshima.
|
|
|
Ref.
|
|
Biochim Biophys Acta, 2009,
1794,
1496-1504.
|
|
|
PubMed id
|
|
|
|
|
Note: In the PDB file this reference is
annotated as "TO BE PUBLISHED". The citation details given above have
been manually determined.
|
|
|
|
Abstract
|
|
|
Tartrate oxidation activity was found in the crude extract of an aerobic
hyperthermophilic archaeon Aeropyrum pernix, and the enzyme was identified as
(S)-malate dehydrogenase (MDH), which, when produced in Escherichia coli, was
mainly obtained as an inactive inclusion body. The inclusion body was dissolved
in 6 M guanidine-HCl and gradually refolded to the active enzyme through
dilution of the denaturant. The purified recombinant enzyme consisted of four
identical subunits with a molecular mass of about 110 kDa. NADP was preferred as
a coenzyme over NAD for (S)-malate oxidation and, unlike MDHs from other
sources, this enzyme readily catalyzed the oxidation of (2S,3S)-tartrate and
(2S,3R)-tartrate. The tartrate oxidation activity was also observed in MDHs from
the hyperthermophilic archaea Methanocaldococcus jannaschii and Archaeoglobus
fulgidus, suggesting these hyperthermophilic MDHs loosely bind their substrates.
The refolded A. pernix MDH was also crystallized, and the structure was
determined at a resolution of 2.9 A. Its overall structure was similar to those
of the M. jannaschii, Chloroflexus aurantiacus, Chlorobium vibrioforme and
Cryptosporidium parvum [lactate dehydrogenase-like] MDHs with
root-mean-square-deviation values between 1.4 and 2.1 A. Consistent with earlier
reports, Ala at position 53 was responsible for coenzyme specificity, and the
next residue, Arg, was important for NADP binding. Structural comparison
revealed that the hyperthermostability of the A. pernix MDH is likely
attributable to its smaller cavity volume and larger numbers of ion pairs and
ion-pair networks, but the molecular strategy for thermostability may be
specific for each enzyme.
|
|
|
|
|
|
|
