Phosphoribulokinase (PRK) is a key enzyme in the Calvin cycle of autotrophic organisms. We have constructed a spinach leaf cDNA library in the phage expression vector, lambda gt11, and used a rabbit polyclonal antibody raised against spinach PRK to identify PRK clones. Analyses of the nucleotide sequences of two antibody-positive clones, 1.47 and 1.35 kb in length, showed that they encode a protein which contains the N-terminal amino acid (aa) sequence [Porter et al., Arch. Biochem. Biophys. 245 (1986) 14-23] of mature spinach PRK. The codon for the N-terminal serine of the mature protein occurs 170 bp from the 5' end of the open reading frame (ORF), suggesting that PRK is synthesized with a rather long transit peptide which is removed from the mature enzyme. The ORF, ending with an amber (TAG) codon at position 1054, predicts a mature enzyme of 351 aa with a calculated Mr of 39232.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/0378-1119(88)90224-7 | DOI Listing |
Photosynth Res
September 2006
Laboratory of Molecular Plant Physiology, Department of Evolutionary Experimental Biology, University of Bologna, Via Irnerio 42, Bologna, 40126, Italy.
Regulation of the Calvin-Benson cycle under varying light/dark conditions is a common property of oxygenic photosynthetic organisms and photosynthetic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is one of the targets of this complex regulatory system. In cyanobacteria and most algae, photosynthetic GAPDH is a homotetramer of GapA subunits which do not contain regulatory domains. In these organisms, dark-inhibition of the Calvin-Benson cycle involves the formation of a kinetically inhibited supramolecular complex between GAPDH, the regulatory peptide CP12 and phosphoribulokinase.
View Article and Find Full Text PDFPlant Physiol
March 2005
Institute of Plant Biochemistry, University of Düsseldorf, 40225 Duesseldorf, Germany.
The chloroplast enzyme phosphoribulokinase (PRK; EC 2.7.1.
View Article and Find Full Text PDFPlant Cell Physiol
March 2003
Department of Applied Biochemistry, Graduate School of Agriculture and Bioscience, Osaka Prefecture University, Gakuen-cho 1-1 Sakai, Osaka, 599-8531 Japan.
We isolated and characterized a gene encoding phosphoribulokinase (PRK) from Synechococcus sp. PCC 7942. The isolated sequence consisted of a 999 bp open reading frame encoding 333 amino acid residues of PRK.
View Article and Find Full Text PDFEur J Biochem
November 2002
Plant Physiology, University of Osnabrueck, Germany; Planton GmbH, Kiel, Germany.
Light/dark modulation of the higher plant Calvin-cycle enzymes phosphoribulokinase (PRK) and NADP-dependent glyceraldehyde 3-phosphate dehydrogenase (NADP- GAPDH-A2B2) involves changes of their aggregation state in addition to redox changes of regulatory cysteines. Here we demonstrate that plants possess two different complexes containing the inactive forms (a) of NADP-GAPDH and PRK and (b) of only NADP-GAPDH, respectively, in darkened chloroplasts. While the 550-kDa PRK/GAPDH/CP12 complex is dissociated and activated upon reduction alone, activation and dissociation of the 600-kDa A8B8 complex of NADP-GAPDH requires incubation with dithiothreitol and the effector 1,3-bisphosphoglycerate.
View Article and Find Full Text PDFJ Biol Chem
June 2000
University of Tennessee-Oak Ridge Graduate School of Biomedical Sciences and the Protein Engineering Program, Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Despite little supportive data, differential target protein susceptibility to redox regulation by thioredoxin (Trx) f and Trx m has been invoked to account for two distinct Trxs in chloroplasts. However, this postulate has not been rigorously tested with phosphoribulokinase (PRK), a fulcrum for redox regulation of the Calvin cycle. Prerequisite to Trx studies, the activation of spinach PRK by dithiothreitol, 2-mercaptoethanol, and glutathione was examined.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!