Arundinella hirta L. is a C(4) plant having an unusual C(4) leaf anatomy. Besides mesophyll and bundle sheath cells, A. hirta leaves have specialized parenchyma cells which look morphologically like bundle sheath cells but which lack vascular connections and are located between veins, running parallel to them. Activities of phosphoenolpyruvate and ribulose-1,5-bisphosphate carboxylases and phos...

Succinate fermentation was investigated in Escherichia coli strains overexpressing Actinobacillus succinogenes phosphoenolpyruvate carboxykinase (PEPCK). In E. coli K-12, PEPCK overexpression had no effect on succinate fermentation. In contrast, in the phosphoenolpyruvate carboxylase mutant E. coli strain K-12 ppc::kan, PEPCK overexpression increased succinate production 6.5-fold.

PepCs isolated from lactic acid bacteria and bleomycin hydrolases of eukaryotic organisms are strict aminopeptidases which belong to the papain family of thiol peptidases. The structural basis of the enzymic specificity of the lactococcal PepC has been investigated by site-directed mutagenesis. The deletion of the C-terminal residue (Ala-435) abolished the aminopeptidase activity, whereas this ...

The chemical modification of phosphoenolpyruvate carboxylase purified from Crassula argentea leaves was studied using the fluorescence of the extrinsic probe 8-anilino-1-naphalenesulfonate. The effects of ligands on kinetic parameters of phosphoenolpyruvate carboxylase activity, and its response to pH and metal cations, were associated with the binding of the ligands to the enzyme as measured b...

Pyruvate kinase (EC 2.7.1.40) is an enzyme with high activity in most tissues. Phosphoenolpyruvate carboxykinase (EC 4.1 .I .32) always has a restricted distribution. In vertebrates phosphoenolpyruvate carboxykinase is found in tissues, such as liver and kidney cortex, with highgluconeogenicactivities (Scrutton & Utter, 1968). In thesetissues the enzyme operates together with pyruvate carboxyla...

CAM and C4 photosynthesis are two key plant adaptations that have evolved independently multiple times, and are especially prevalent in particular groups of plants, including the Caryophyllales. We investigate the origin of photosynthetic PEPC, a key enzyme of both the CAM and C4 pathways. We combine phylogenetic analyses of genes encoding PEPC with analyses of RNA sequence data of Portulaca, t...

Daniel H. Gonzalez and Carlos S. Andreo Centro de Estudios Fotosinteticos y Bioqui'micos, Suipacha 531. 2000 Rosario. Argentina Z. Naturforsch. 41c, 1004—1010 (1986); received June 23/August 15, 1986 Phosphoenolpyruvate Carboxylase, Phosphoenolpyruvate Analogues, Reaction Mechanism, Maize Leaf 1. The phosphoenolpyruvate analogues phosphoenol-a-ketobutyrate and phosphoenol-aketoisovalerate are l...

In Methanothermobacter thermautotrophicus, oxaloacetate synthesis is a major and essential CO(2)-fixation reaction. This methanogenic archaeon possesses two oxaloacetate-synthesizing enzymes, pyruvate carboxylase and phosphoenolpyruvate carboxylase. The phosphoenolpyruvate carboxylase from this organism was purified to homogeneity. The subunit size of this homotetrameric protein was 55 kDa, whi...