2X06: Sulfolactate Dehydrogenase From Methanocaldococcus Jannaschii

The crystal structure of the sulfolactate dehydrogenase from the hyperthermophilic and methanogenic archaeon Methanocaldococcus jannaschii was solved at 2.5 A resolution (PDB id. 1RFM). The asymmetric unit contains a tetramer of tight dimers. This structure, complexed with NADH, does not contain a cofactor-binding domain with 'Rossmann-fold' topology. Instead, the tertiary and quaternary structures indicate a novel fold. The NADH is bound in an extended conformation in each active site, in a manner that explains the pro-S specificity. Cofactor binding involves residues belonging to both subunits within the tight dimers, which are therefore the smallest enzymatically active units. The protein was found to be a homodimer in solution by size-exclusion chromatography, analytical ultracentrifugation and small-angle neutron scattering. Various compounds were tested as putative substrates. The results indicate the existence of a substrate discrimination mechanism, which involves electrostatic interactions. Based on sequence homology and phylogenetic analyses, several other enzymes were classified as belonging to this novel family of homologous (S)-2-hydroxyacid dehydrogenases.
PDB ID: 2X06Download
MMDB ID: 78698
PDB Deposition Date: 2009/12/7
Updated in MMDB: 2009/12
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 2X06: dimeric; determined by author and by software (PISA)
Molecular Components in 2X06
Label Count Molecule
Proteins (2 molecules)
L-sulfolactate Dehydrogenase(Gene symbol: MJ_RS07630)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB