4ZGS: Identification of the pyruvate reductase of Chlamydomonas reinhardtii

Citation:
Abstract
Under anoxic conditions the green alga Chlamydomonas reinhardtii activates various fermentation pathways leading to the creation of formate, acetate, ethanol and small amounts of other metabolites including d-lactate and hydrogen. Progress has been made in identifying the enzymes involved in these pathways and their subcellular locations; however, the identity of the enzyme involved in reducing pyruvate to d-lactate has remained unclear. Based on sequence comparisons, enzyme activity measurements, X-ray crystallography, biochemical fractionation and analysis of knock-down mutants, we conclude that pyruvate reduction in the chloroplast is catalyzed by a tetrameric NAD(+)-dependent d-lactate dehydrogenase encoded by Cre07.g324550. Its expression during aerobic growth supports a possible function as a 'lactate valve' for the export of lactate to the mitochondrion for oxidation by cytochrome-dependent d-lactate dehydrogenases and by glycolate dehydrogenase. We also present a revised spatial model of fermentation based on our immunochemical detection of the likely pyruvate decarboxylase, PDC3, in the cytoplasm.
PDB ID: 4ZGSDownload
MMDB ID: 134540
PDB Deposition Date: 2015/4/23
Updated in MMDB: 2015/12
Experimental Method:
x-ray diffraction
Resolution: 2.461  Å
Source Organism:
Similar Structures:
Biological Unit for 4ZGS: tetrameric; determined by author and by software (PISA)
Molecular Components in 4ZGS
Label Count Molecule
Proteins (4 molecules)
4
Putative D-lactate Dehydrogenase
Molecule annotation
Chemicals (4 molecules)
1
4
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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