NMR structures of thioredoxin m from the green alga Chlamydomonas reinhardtii.Lancelin, J.M., Guilhaudis, L., Krimm, I., Blackledge, M.J., Marion, D., Jacquot, J.P.
(2000) Proteins 41: 334-349
- PubMed: 11025545
- PubMed Abstract:
- Chlamydomonas reinhardtii Thioredoxins: Structure of the Genes Coding for Chloroplastic m and Cytosolic h Isoforms; Expression in Escherichia coli of the Recombinant Proteins, Purification and Biochemical Properties
Stein, M.,Jacquot, J.-P.,Jeannette, E.,Decottignies, P.,Hodges, M.,Lancelin, J.-M.,Mittard, V.,Schmitter, J.M.,Miginiac-Maslow, M.
(1995) Plant Mol.Biol. 28: 487
- Secondary Structure and Protein Folding of Recombinant Chloroplastic Thioredoxin Ch2 from the Green Alga Chlamydomonas reinhardtii as Determined by 1H NMR
Lancelin, J.-M.,Stein, M.,Jacquot, J.-P.
(1993) J.Biochem.(Tokyo) 114: 421
- PCR Cloning of a Nucleotidic Sequence Coding for the Mature Part of Chlamydomonas reinhardtii Thioredoxin Ch2
Jacquot, J.-P.,Stein, M.,Hodges, M.,Miginiac-Maslow, M.
(1992) Nucleic Acids Res. 20: 617
Chloroplast thioredoxin m from the green alga Chlamydomomas reinhardtii is very efficiently reduced in vitro and in vivo in the presence of photoreduced ferredoxin and a ferredoxin dependent ferredoxin-thioredoxin reductase. Once reduced, thioredoxin ...
Chloroplast thioredoxin m from the green alga Chlamydomomas reinhardtii is very efficiently reduced in vitro and in vivo in the presence of photoreduced ferredoxin and a ferredoxin dependent ferredoxin-thioredoxin reductase. Once reduced, thioredoxin m has the capability to quickly activate the NADP malate dehydrogenase (EC 18.104.22.168) a regulatory enzyme involved in an energy-dependent assimilation of carbon dioxide in C4 plants. This activation is the result of the reduction of two disulfide bridges by thioredoxin m, that are located at the N- and C-terminii of the NADP malate dehydrogenase. The molecular structure of thioredoxin m was solved using NMR and compared to other known thioredoxins. Thioredoxin m belongs to the prokaryotic type of thioredoxin, which is divergent from the eukaryotic-type thioredoxins also represented in plants by the h (cytosolic) and f (chloroplastic) types of thioredoxins. The dynamics of the molecule have been assessed using (15)N relaxation data and are found to correlate well with regions of disorder found in the calculated NMR ensemble. The results obtained provide a novel basis to interpret the thioredoxin dependence of the activation of chloroplast NADP-malate dehydrogenase. The specific catalytic mechanism that takes place in the active site of thioredoxins is also discussed on the basis of the recent new understanding and especially in the light of the dual general acid-base catalysis exerted on the two cysteines of the redox active site. It is proposed that the two cysteines of the redox active site may insulate each other from solvent attack by specific packing of invariable hydrophobic amino acids.
Laboratoire de RMN Biomoléculaire associé au CNRS, Université Claude Bernard-Lyon 1 and Ecole Supérieure de Chimie, Physique et Electronique de Lyon, Villeurbanne, France. firstname.lastname@example.org