Phosphoenolpyruvate carboxylase (PEPC) catalyzes the irreversible carboxylation of phosphoenolpyruvate (PEP) and plays a crucial role in fixing atmospheric CO(2) in C(4) and CAM plants. The enzyme is widespread in plants and bacteria and mostly regulated allosterically by both positive and negative effectors. Archaeal PEPCs (A-PEPCs) have unique characteristics in allosteric regulation and mole...

Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) is an important cytosolic regulatory enzyme that plays a pivotal role in numerous physiological processes in plants, including seed development and germination. Previous studies demonstrated the occurrence of immunoreactive PEPC polypeptides of ~110 kDa and 107 kDa (p110 and p107, respectively) on immunoblots of clarified extracts of germinati...

The interactive effects of light and temperature on C(4) phosphoenolpyruvate carboxylase (PEPC) were examined both in vivo and in situ using the leaves of Amaranthus hypochondriacus collected at different times during a day and in each month during the year. The maximum activity of PEPC, least inhibition by malate, and highest activation by glucose-6-phosphate were at 15.00 h during a typical d...

Phosphoenolpyruvate carboxylase (PEPC) is an important enzyme for CO2 fixation and primary metabolism in photosynthetic organisms including cyanobacteria. The kinetics and allosteric regulation of PEPCs have been studied in many organisms, but the biochemical properties of PEPC in the unicellular, non-nitrogen-fixing cyanobacterium Synechocystis sp. PCC 6803 have not been clarified. In this stu...

Phosphoenolpyruvate carboxylase (PEPC) plays a crucial role in the assimilation of CO2 during symbiotic N2 fixation in legume root nodules. In this study, an alfalfa PEPC gene (PEPC-7), whose transcripts are found at elevated levels in nodules relative to either leaves or roots, has been isolated and characterized. The intron/exon structure of this gene is identical to that of most other plant ...

C4 photosynthesis involves a close collaboration of the C3 and C4 metabolic cycles across the mesophyll and bundle-sheath cells. This study investigated the coordination of C4 photosynthesis in maize plants subjected to two salinity (50 and 100mM NaCl) treatments and one shade (20% of full sunlight) treatment. Photosynthetic efficiency was probed by combining leaf gas-exchange measurements with...

Phosphoenolpyruvate carboxylase (PEPC) is a key enzyme of primary metabolism in bacteria, algae, and vascular plants, and is believed to be cytosolic. Here we show that rice (Oryza sativa L.) has a plant-type PEPC, Osppc4, that is targeted to the chloroplast. Osppc4 was expressed in all organs tested and showed high expression in the leaves. Its expression in the leaves was confined to mesophyl...

The mechanisms of carbon concentration in marine diatoms are controversial. At low CO2 , decreases in O2 evolution after inhibition of phosphoenolpyruvate carboxylases (PEPCs), and increases in PEPC transcript abundances, have been interpreted as evidence for a C4 mechanism in Thalassiosira pseudonana, but the ascertainment of which proteins are responsible for the subsequent decarboxylation an...

Phosphoenolpyruvate carboxylase (PEPC) is a tightly regulated anaplerotic enzyme situated at a major branch point of the plant C metabolism. Two distinct oligomeric classes of PEPC occur in the triglyceride-rich endosperm of developing castor oil seeds (COS). Class-1 PEPC is a typical homotetramer composed of identical 107-kDa plant-type PEPC (PTPC) subunits (encoded by RcPpc3), whereas the nov...

Introducing a C(4)-like pathway into C(3) plants is one of the proposed strategies for the enhancement of photosynthetic productivity. For this purpose it is necessary to provide each component enzyme that exerts strong activity in the targeted C(3) plants. Here, a maize C(4)-form phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) was engineered for its regulatory and catalytic properties so a...