Stucture of phospho<i>enol</i>pyruvate carboxylase from maize leaves

Stiborová, Marie; Leblová, Sylva

doi:10.1016/0014-5793(86)80860-2

Cited by 16 publications

(11 citation statements)

References 11 publications

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“…The reduction of two disulfide bonds per tetramer seems to be involved in the activation by dithiothreitol and other thiol compounds ( [32]; see section 5.1). Recently, some of these results were confirmed and it was established that the native enzyme contains 8 disulfide bonds [60].…”

Section: Structurementioning

confidence: 86%

Higher plant phosphoenolpyruvate carboxylase

1987

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Section: Structurementioning

confidence: 86%

Higher plant phosphoenolpyruvate carboxylase

1987

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“…With respect to the molecular structure of the C4 plant enzyme, only recently some reports have presented evidence on the possible spatial arrangement of the carboxylase molecule (1,25,27). Further evidence comes from the dissociation observed after chemical modification of histidine or thiol groups (28) or after exposure to increasing ionic strength (26).…”

mentioning

confidence: 99%

Maize Leaf Phosphoenolpyruvate Carboxylase

Podestá

Andreo²

1989

Plant Physiol.

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Maize (Zea mays L.) leaf phosphoenolpyruvate (PEP) carboxylase activity at subsaturating levels of PEP was increased by the inclusion of glycerol (20%, v/v) in the assay medium. The extent of activation was dependent on H+ concentration, being more marked at pH 7 (with activities 100% higher than in aqueous medium) than at pH 8 (20% activation). The determination of the substrate concentration necessary to achieve half-maximal enzyme activity (So.5) (PEP) and maximal velocity (V) between pH 6.9 and 8.2 showed a uniform decrease in So.5 in the presence of glycerol over the entire pH range tested, and only a slight decrease in V at pH values near 8. Including NaCI (100 millimolar) in the glycerol containing assay medium resulted in additional activation, mainly due to an increase in V over the entire range of pH. Glucose-6-phosphate (5 millimolar) activated both the native and the glycerol-treated enzyme almost to the same extent, at pH 7 and I millimolar PEP. Inhibition by 5 millimolar malate at pH 7 and subsaturating PEP was considerably lower in the presence of glycerol than in an aqueous medium (8% against 25%, respectively). Size-exclusion high performance liquid chromatography in aqueous buffer revealed the existence of an equilibrium between the tetrameric and dimeric enzyme forms, which is displaced to the tetramer as the pH was increased from 7 to 8. In the presence of glycerol, only the 400 kilodalton tetrameric form was observed at pH 7 or 8. However, dissociation into dimers by NaCI could not be prevented by the polyol. We conclude that the control of the aggregation state by the metabolic status of the cell could be one regulatory mechanism of PEP carboxylase.The C4 pathway of carbon fixation is a highly specialized metabolism, the main effect of which is to increase the concentration of CO2 in the bundle sheath cells (7), therefore optimizing the function of the ribulose-1 ,5-bisphosphate carboxylase/oxygenase in the direction of carboxylation, and decreasing energy losses by photorespiration.An important enzyme in this metabolism is PEPC2 (EC

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“…[15] showed significant differences in several species of amino acids. The reason for this discrepancy remains unknown at present.…”

Section: Ttagcttcccgccgcgccatggcgtcgaccaaggcacccggccctggcgagaagcaccacmentioning

confidence: 97%

“…From the deduced amino acid sequence, together with the previous data [7], maize PEPC was supposed to be composed of 970 amino acid residues with a molecular mass of 109408 Da. [15] showed significant differences in several species of amino acids. The reason for this discrepancy remains unknown at present.…”

Section: Sequence Analysis Of the 5 '-Terminal Regionmentioning

confidence: 97%

Further analysis of cDNA clones for maize phosphoenolpyruvate carboxylase involved in C₄ photosynthesis Nucleotide sequence of entire open reading frame and evidence for polyadenylation of mRNA at multiple sites in vivo

et al. 1988

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Four clones of cDNA for phosphoenolpyruvate carboxylase [EC 4.1.1.31] were obtained from a maize green leaf eDNA library by colony hybridization. The largest eDNA was of full-length (3335 nucleotides), being 243 nucleotides longer than the cDNA cloned previously ) Nucleic Acids Res. 14, 1615-1628. Alignment of the sequence for the N-terminal coding region found in two of the four clones with the sequence reported previously, established the sequence of the entire coding region for the enzyme. The sequencing of 3'-untranslated region of the clones revealed that the poly (A) tract is attached at multiple sites in vivo.

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Stucture of phosphoenolpyruvate carboxylase from maize leaves

Cited by 16 publications

References 11 publications

Higher plant phosphoenolpyruvate carboxylase

Higher plant phosphoenolpyruvate carboxylase

Maize Leaf Phosphoenolpyruvate Carboxylase

Further analysis of cDNA clones for maize phosphoenolpyruvate carboxylase involved in C₄ photosynthesis Nucleotide sequence of entire open reading frame and evidence for polyadenylation of mRNA at multiple sites in vivo

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Stucture of phosphoenolpyruvate carboxylase from maize leaves

Cited by 16 publications

References 11 publications

Higher plant phosphoenolpyruvate carboxylase

Higher plant phosphoenolpyruvate carboxylase

Maize Leaf Phosphoenolpyruvate Carboxylase

Further analysis of cDNA clones for maize phosphoenolpyruvate carboxylase involved in C4 photosynthesis Nucleotide sequence of entire open reading frame and evidence for polyadenylation of mRNA at multiple sites in vivo

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Further analysis of cDNA clones for maize phosphoenolpyruvate carboxylase involved in C₄ photosynthesis Nucleotide sequence of entire open reading frame and evidence for polyadenylation of mRNA at multiple sites in vivo