title: Identification and expression analysis of a gene encoding a bacterial-type phosphoenolpyruvate carboxylase from Arabidopsis and rice.
abstract: Phosphoenolpyruvate carboxylase (PEPC) is distributed in plants and bacteria but is not found in fungi and animal cells. Important motifs for enzyme activity and structure are conserved in plant and bacterial PEPCs, with the exception of a phosphorylation domain present at the N terminus of all plant PEPCs reported so far, which is absent in the bacterial enzymes. Here, we describe a gene from Arabidopsis, stated as Atppc4, encoding a PEPC, which shows more similarity to Escherichia coli than to plant PEPCs. Interestingly, this enzyme lacks the phosphorylation domain, hence indicating that it is a bacterial-type PEPC. Three additional PEPC genes are present in Arabidopsis, stated as Atppc1, Atppc2, and Atppc3, encoding typical plant-type enzymes. As most plant PEPC genes, Atppc1, Atppc2, and Atppc3 are formed by 10 exons interrupted by nine introns. In contrast, Atppc4 gene has an unusual structure formed by 20 exons. A bacterial-type PEPC gene was also identified in rice (Oryza sativa), stated as Osppc-b, therefore showing the presence of this type of PEPC in monocots. The phylogenetic analysis suggests that both plant-type and bacterial-type PEPCs diverged early during the evolution of plants from a common ancestor, probably the PEPC from gamma-proteobacteria. The diversity of plant-type PEPCs in C3, C4, and Crassulacean acid metabolism plants is indicative of the evolutionary success of the regulation by phosphorylation of this enzyme. Although at a low level, the bacterial-type PEPC genes are expressed in Arabidopsis and rice.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Avda Américo Vespucio s/n, 41092-Sevilla, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Sánchez
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Cejudo
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D001483:Base Sequence; D000458:Cyanobacteria / Q000201:enzymology / Q000235:genetics; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D012275:Oryza / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D010730:Phosphoenolpyruvate Carboxylase / Q000737:chemistry / Q000235:genetics*; D010802:Phylogeny; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D018749:RNA, Plant; D010730:Phosphoenolpyruvate Carboxylase