Chlamydomonas reinhardtii

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/09/06 17:39:17」(JST)

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English Journal

Enzymatic characterization of Chlamydomonas reinhardtii glycolate dehydrogenase and its nearest proteobacterial homologue.

Aboelmy MH1, Peterhansel C2.Author information 1Leibniz University Hannover, Institute of Botany, Herrenhäuser Straße 2, 30419 Hannover, Germany.2Leibniz University Hannover, Institute of Botany, Herrenhäuser Straße 2, 30419 Hannover, Germany. Electronic address: cp@botanik.uni-hannover.de.AbstractChlamydomonas reinhardtii contains a unique glycolate dehydrogenase (CrGlcDH) for glycolate oxidation in photorespiration that is different in structure from the GlcDH enzymes of heteroptrophic prokaryotes and the glycolate oxidases of higher plants. Here, we purified the recombinantly overexpressed enzyme and characterized its enzymatic properties. CrGlcDH uses D-lactate, but not l-lactate, as an alternative substrate with similar catalytic efficiency compared to glycolate. Other short-chain organic acids are only very slowly oxidized. Only the artificial electron acceptors DCIP and PMS, but neither flavine mono- or dinucleotides nor nicotinamide dinucleotides or cytochrome c, were used as electron acceptors by the recombinant enzyme. The enzyme is sensitive to CuSO4 suggesting function of reactive sulfhydryl groups in catalysis. Accordingly, mutational analysis of a putative Fe-S cluster indicated an important function of this domain in catalysis. Evolutionary sequence analysis confirmed that CrGlcDH belongs to a so far biochemically uncharacterized group of enzymes that is found in chlorophytes and some proteobacteria. The most related proteobacterial homologue was only active with d-lactate, but not glycolate as a substrate. Our results indicate that in the chlorophytes an existing enzyme changed its substrate specificity to support photorespiratory glycolate oxidation.
Plant physiology and biochemistry : PPB / Société française de physiologie végétale.Plant Physiol Biochem.2014 Jun;79:25-30. doi: 10.1016/j.plaphy.2014.03.009. Epub 2014 Mar 19.
Chlamydomonas reinhardtii contains a unique glycolate dehydrogenase (CrGlcDH) for glycolate oxidation in photorespiration that is different in structure from the GlcDH enzymes of heteroptrophic prokaryotes and the glycolate oxidases of higher plants. Here, we purified the recombinantly overexpressed
PMID 24681750

In vitro characterization of bacterial and chloroplast Hsp70 systems reveals an evolutionary optimization of the co-chaperones for their Hsp70 partner.

Veyel D, Sommer F1, Muranaka LS1, Rütgers M1, Lemaire SD2, Schroda M1.Author information 1*Molekulare Biotechnologie and Systembiologie, TU Kaiserslautern, Paul-Ehrlich-Strasse 23, D-67663 Kaiserslautern, Germany.2‡Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, FRE3354, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, 75005 Paris, France.AbstractThe chloroplast Hsp70 (heat-shock protein of 70 kDa) system involved in protein folding in Chlamydomonas reinhardtii consists of HSP70B, the DnaJ homologue CDJ1 and the GrpE-type nucleotide-exchange factor CGE1. The finding that HSP70B needs to be co-expressed with HEP2 (Hsp70 escort protein 2) to become functional allowed the reconstitution of the chloroplast Hsp70 system in vitro and comparison with the homologous Escherichia coli system. Both systems support luciferase refolding and display ATPase and holdase activities. Steady-state activities are low and strongly stimulated by the co-chaperones, whose concentrations need to be balanced to optimally support luciferase refolding. Although the co-chaperones of either system generally stimulate ATPase and folding-assistance activities of the other, luciferase refolding is reduced ~10-fold and <2-fold if either Hsp70 is supplemented with the foreign DnaJ and GrpE protein respectively, suggesting an evolutionary specialization of the co-chaperones for their Hsp70 partner. Distinct features are that HSP70B's steady-state ATPase exhibits ~20-fold higher values for Vmax and Km and that the HSP70B system displays a ~6-fold higher folding assistance on denatured luciferase. Although truncating up to 16 N-terminal amino acids of CGE1 does not affect HSP70B's general ATPase and folding-assistance activities in the physiological temperature range, further deletions hampering dimerization of CGE1 via its N-terminal coiled coil do.
The Biochemical journal.Biochem J.2014 May 15;460(1):13-24. doi: 10.1042/BJ20140001.
The chloroplast Hsp70 (heat-shock protein of 70 kDa) system involved in protein folding in Chlamydomonas reinhardtii consists of HSP70B, the DnaJ homologue CDJ1 and the GrpE-type nucleotide-exchange factor CGE1. The finding that HSP70B needs to be co-expressed with HEP2 (Hsp70 escort protein 2) to
PMID 24564700

Respiratory-deficient mutants of the unicellular green alga Chlamydomonas: A review.

Salinas T1, Larosa V2, Cardol P2, Maréchal-Drouard L1, Remacle C3.Author information 1Institut de Biologie Moléculaire des Plantes, UPR CNRS 2357, Associated with Université de Strasbourg, 67084 Strasbourg Cedex, France.2Génétique des Microorganismes, Département de Sciences de la Vie, Institut de Botanique, B22, Université de Liège, B-4000 Liège, Belgium.3Génétique des Microorganismes, Département de Sciences de la Vie, Institut de Botanique, B22, Université de Liège, B-4000 Liège, Belgium. Electronic address: c.remacle@ulg.ac.be.AbstractGenetic manipulation of the unicellular green alga Chlamydomonas reinhardtii is straightforward. Nuclear genes can be interrupted by insertional mutagenesis or targeted by RNA interference whereas random or site-directed mutagenesis allows the introduction of mutations in the mitochondrial genome. This, combined with a screen that easily allows discriminating respiratory-deficient mutants, makes Chlamydomonas a model system of choice to study mitochondria biology in photosynthetic organisms. Since the first description of Chlamydomonas respiratory-deficient mutants in 1977 by random mutagenesis, many other mutants affected in mitochondrial components have been characterized. These respiratory-deficient mutants increased our knowledge on function and assembly of the respiratory enzyme complexes. More recently some of these mutants allowed the study of mitochondrial gene expression processes poorly understood in Chlamydomonas. In this review, we update the data concerning the respiratory components with a special focus on the assembly factors identified on other organisms. In addition, we make an inventory of different mitochondrial respiratory mutants that are inactivated either on mitochondrial or nuclear genes.
Biochimie.Biochimie.2014 May;100C:207-218. doi: 10.1016/j.biochi.2013.10.006. Epub 2013 Oct 15.
Genetic manipulation of the unicellular green alga Chlamydomonas reinhardtii is straightforward. Nuclear genes can be interrupted by insertional mutagenesis or targeted by RNA interference whereas random or site-directed mutagenesis allows the introduction of mutations in the mitochondrial genome. T
PMID 24139906

Japanese Journal

A Green and Biocompatible Magnetically Powered Nickel–Flagella Nanomotor

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Chemistry Letters 44(3), 300-302, 2015
… The nanomotor was readily prepared using a streptavidin-coated Au/Ni/Au nanowire and biotinylated-isolated flagella obtained from Chlamydomonas reinhardtii. …
NAID 130004868386

A Green/Biocompatible Magnetically Powered Nickel-Flagella Nanomotor

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Chemistry Letters advpub(0), 2015
… The nanomotor was readily prepared using a streptavidin-coated Au/Ni/Au nanowire and a biotinylated-isolated flagella obtained from Chlamydomonas reinhardtii. …
NAID 130004712956

Computational comparison of mediated current generation capacity of Chlamydomonas reinhardtii in photosynthetic and respiratory growth modes(BIOCHEMICAL ENGINEERING)

Mao Longfei,Verwoerd Wynand S.
Journal of bioscience and bioengineering 118(5), 565-574, 2014-11
… Chlamydomonas reinhardtii possesses many potential advantages to be exploited as a biocatalyst in microbial fuel cells (MFCs) for electricity generation. … reinhardtii for current output and identify the metabolic mechanisms supporting a high current generation in three different cultivation conditions, i.e., heterotrophic, photoautotrophic and mixotrophic growth. …
NAID 110009894843