Journal article
Folate synthesis in plants: The p-aminobenzoate branch is initiated by a bifunctional PabA-PabB protein that is targeted to plastids
Proceedings of the National Academy of Sciences - PNAS, Vol.101(6), pp.1496-1501
02/10/2004
DOI: 10.1073/pnas.0308331100
PMCID: PMC341757
PMID: 14745019
Abstract
It is not known how plants synthesize the
p
-aminobenzoate (PABA) moiety of folates. In
Escherichia coli
, PABA is made from chorismate in two steps. First, the PabA and PabB proteins interact to catalyze transfer of the amide nitrogen of glutamine to chorismate, forming 4-amino-4-deoxychorismate (ADC). The PabC protein then mediates elimination of pyruvate and aromatization to give PABA. Fungi, actinomycetes, and
Plasmodium
spp. also synthesize PABA but have proteins comprising fused domains homologous to PabA and PabB. These bipartite proteins are commonly called “PABA synthases,” although it is unclear whether they produce PABA or ADC. Genomic approaches identified
Arabidopsis
and tomato cDNAs encoding bipartite proteins containing fused PabA and PabB domains, plus a putative chloroplast targeting peptide. These cDNAs encode functional enzymes, as demonstrated by complementation of an
E. coli pabA pabB
double mutant and a yeast PABA-synthase deletant. The partially purified recombinant
Arabidopsis
protein did not produce PABA unless the
E. coli
PabC enzyme was added, indicating that it forms ADC, not PABA. The enzyme behaved as a monomer in size-exclusion chromatography and was not inhibited by physiological concentrations of PABA, its glucose ester, or folates. When the putative targeting peptide was fused to GFP and expressed in protoplasts, the fusion protein appeared only in chloroplasts, indicating that PABA synthesis is plastidial. In the pericarp of tomato fruit, the PabA-PabB mRNA level fell drastically as ripening advanced, but there was no fall in total PABA content, which stayed between 0.7 and 2.3 nmol·g
-1
fresh weight.
Details
- Title: Subtitle
- Folate synthesis in plants: The p-aminobenzoate branch is initiated by a bifunctional PabA-PabB protein that is targeted to plastids
- Creators
- Gilles J. C Basset - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Eoin P Quinlivan - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Stéphane Ravanel - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Fabrice Rébeillé - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Brian P Nichols - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Kazuo Shinozaki - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Motoaki Seki - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Lori C Adams-Phillips - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853James J Giovannoni - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Jesse F Gregory - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853Andrew D Hanson - Departments of Horticultural Sciences and Food Science and Human Nutrition, University of Florida, Gainesville, FL 32611; Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique/Commissariat à l'Energie Atomique/Institut National de la Recherche Agronomique/Université Joseph Fourier, Commissariat à l'Energie Atomique-Grenoble, F-38054 Grenoble Cedex 9, France; Department of Biological Sciences, University of Illinois, Chicago, IL 60607; Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305-0074, Japan; Plant Mutation Exploration Team, Plant Functional Genomics Research Group, RIKEN Genomic Sciences Center, Yokohama, Kanagawa 230-0045, Japan; and United States Department of Agriculture-Agricultural Research Service and Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, Vol.101(6), pp.1496-1501
- DOI
- 10.1073/pnas.0308331100
- PMID
- 14745019
- PMCID
- PMC341757
- NLM abbreviation
- Proc Natl Acad Sci U S A
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Publisher
- National Academy of Sciences
- Language
- English
- Date published
- 02/10/2004
- Academic Unit
- Biology
- Record Identifier
- 9984217536902771
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