Enhanced chloroplastic generation of H2O2 in stress-resistant Thellungiella salsuginea in comparison to Arabidopsis thaliana.

In order to find some basis of salinity resistance in the chloroplastic metabolism, a halophytic Thellungiella salsuginea was compared with glycophytic Arabidopsis thaliana. In control T.s.

On the mode of integration of the thylakoid membrane protein cytochrome b(6) into cytoplasmic membrane of Escherichia coli.

In the stroma compartment, several pathways are used for integration/translocation of chloroplast proteins into or across the thylakoid membrane. In this study we investigated the mode of incorporation of the chloroplast-encoded cytochrome b(6) into the bacterial membrane. Cytochrome b(6) naturally comprises of four transmembrane helices (A,B,C,D) and contains two b-type hemes.

Heterologous expression and initial characterization of recombinant RbcX protein from Thermosynechococcus elongatus BP-1 and the role of RbcX in RuBisCO assembly.

In the cyanobacterial RuBisCO operon from Thermosynechococcus elongatus the rbcX gene is juxtaposed and cotranscribed with the rbcL and rbcS genes which encode large and small RuBisCO subunits, respectively. It has been suggested that the rbcX position is not random and that the RbcX protein could be a chaperone for RuBisCO. In this study, the RbcX protein from T.

Ribulose-1,5-bisphosphate carboxylase/oxygenase from thermophilic cyanobacterium Thermosynechococcus elongatus.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) can be divided into two branches: the "red-like type" of marine algae and the "green-like type" of cyanobacteria, green algae, and higher plants. We found that the "green-like type" rubisco from the thermophilic cyanobacterium Thermosynechococcus elongatus has an almost 2-fold higher specificity factor compared with rubiscos of mesophilic cyanobacteria, reaching the values of higher plants, and simultaneously revealing an improvement in enzyme thermostability. The difference in the activation energies at the transition stages between the oxygenase and carboxylase reactions for Thermosynechococcus elongatus rubisco is very close to that of Galdieria partita and significantly higher than that of spinach.

Iron-sulfur cluster reconstitution of spinach chloroplast Rieske protein requires a partially prefolded apoprotein.

The Rieske 2Fe-2S protein is a central component of the photosynthetic electron transport cytochrome b6f complex in chloroplast and cyanobacterial thylakoid membranes. We have constructed plasmids for expression in Escherichia coli of full-length and truncated Spinacia oleracea Rieske (PetC) proteins fused to the MalE, maltose binding protein. The expressed Rieske fusion proteins were found predominantly in soluble form in the E.

Overexpression and reconstitution of a Rieske iron-sulfur protein from the higher plant.

The iron-sulfur protein subunit, known as the Rieske protein, is one of the central components of the cytochrome b(6)f complex residing in chloroplast and cyanobacterial thylakoid membranes. We have constructed plasmids for overexpression in Escherichia coli of full-length and truncated Rieske (PetC) proteins from the Spinacia oleracea fused to MalE. Overexpressed fusion proteins were predominantly found (from 55 to 70%) in cytoplasm in a soluble form.