4ZGS

Identification of the pyruvate reductase of Chlamydomonas reinhardtii

Summary for 4ZGS

• Entry DOI: 10.2210/pdb4zgs/pdb
• Descriptor: Putative D-lactate dehydrogenase, NICOTINAMIDE-ADENINE-DINUCLEOTIDE (3 entities in total)
• Functional Keywords: pyruvate dehydrogenase, fermentation, green alga, biohydrogen, oxidoreductase
• Biological source: Chlamydomonas reinhardtii
• Total number of polymer chains: 8
• Total formula weight: 341957.90

Authors

Burgess, S.J.,Hussein, T.,Yeoman, J.A.,Iamshanova, O.,Boehm, M.,Bundy, J.,Bialek, W.,Murray, J.W.,Nixon, P.J. (deposition date: 2015-04-23, release date: 2015-12-02, Last modification date: 2024-01-10)

Primary citation

Burgess, S.J.,Taha, H.,Yeoman, J.A.,Iamshanova, O.,Chan, K.X.,Boehm, M.,Behrends, V.,Bundy, J.G.,Bialek, W.,Murray, J.W.,Nixon, P.J.
Identification of the Elusive Pyruvate Reductase of Chlamydomonas reinhardtii Chloroplasts.
Plant Cell.Physiol., 57:82-94, 2016

PubMed 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.

PubMed: 26574578
DOI: 10.1093/pcp/pcv167

Experimental method

X-RAY DIFFRACTION (2.461 Å)