Phosphoenolpyruvate carboxylase: Difference between revisions
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== Overview == | == Overview == | ||
[[Image:C4_photosynthesis_cycle.png|thumb|400px|caption position=bottom| '''Figure 2''' Diagrammatic representation of the C4 photosynthetic pathway | [[Image:C4_photosynthesis_cycle.png|thumb|400px|caption position=bottom| '''Figure 2''' Diagrammatic representation of the C4 photosynthetic pathway ([https://bio.libretexts.org/Courses/Lumen_Learning/Biology_for_Non_Majors_II_%28Lumen%29/10%3A_Module_7-_Plant_Structure_and_Function/10.13%3A_Plant_Photorespiration source])]] | ||
The enzyme phosphoenolpyruvate carboxylase (PEPC) catalyzes the carboxylation of phosphoenolpyruvate to form oxaloacetate, with Mg2+ or Mn2+ as essential cofactors <ref name="kai2003">PMID: 12781768</ref><ref name="svensson2003">PMID: 12781769</ref>. It can be considered the key enzyme in the [https://en.wikipedia.org/wiki/C4_carbon_fixation C4 photosynthesis] process, once it’s a central part of the mechanism that makes C4 plants more efficient in carbon fixation compared to classical C3-photosynthetic pathway plants, especially in abiotic stress environments <ref name="sage2012">PMID: 22404472</ref>. PEPC is a ubiquitous enzyme, present in the genome of all plants. However, the isoforms found in C4 metabolism plants differ in their kinetic and regulatory characteristics, when compared to C3 orthologs <ref name="Paulus2013">PMID: 23443546</ref>. Among the Flaverina genus of the [https://en.wikipedia.org/wiki/Asteraceae Asteraceae] family, closely related C3 and C4 species are found, providing a good model to study the differences between the two processes. The comparative analysis of ''Flaverina pringlei'' (C3) and [https://en.wikipedia.org/wiki/Flaveria_trinervia ''Flaverina trinervia''] (C4) PEPC’s, has shown that the exchange of single amino acids can be responsible for the observed differences in saturation kinetics and inhibitor tolerance between PEPC’s of C3 and C4 species <ref name="blasing2000">PMID: 10871630</ref><ref name="Paulus2013"/>. | The enzyme phosphoenolpyruvate carboxylase (PEPC) catalyzes the carboxylation of phosphoenolpyruvate to form oxaloacetate, with Mg2+ or Mn2+ as essential cofactors <ref name="kai2003">PMID: 12781768</ref><ref name="svensson2003">PMID: 12781769</ref>. It can be considered the key enzyme in the [https://en.wikipedia.org/wiki/C4_carbon_fixation C4 photosynthesis] process, once it’s a central part of the mechanism that makes C4 plants more efficient in carbon fixation compared to classical C3-photosynthetic pathway plants, especially in abiotic stress environments <ref name="sage2012">PMID: 22404472</ref>. PEPC is a ubiquitous enzyme, present in the genome of all plants. However, the isoforms found in C4 metabolism plants differ in their kinetic and regulatory characteristics, when compared to C3 orthologs <ref name="Paulus2013">PMID: 23443546</ref>. Among the Flaverina genus of the [https://en.wikipedia.org/wiki/Asteraceae Asteraceae] family, closely related C3 and C4 species are found, providing a good model to study the differences between the two processes. The comparative analysis of ''Flaverina pringlei'' (C3) and [https://en.wikipedia.org/wiki/Flaveria_trinervia ''Flaverina trinervia''] (C4) PEPC’s, has shown that the exchange of single amino acids can be responsible for the observed differences in saturation kinetics and inhibitor tolerance between PEPC’s of C3 and C4 species <ref name="blasing2000">PMID: 10871630</ref><ref name="Paulus2013"/>. | ||