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. 1992 Sep;4(9):1147–1156. doi: 10.1105/tpc.4.9.1147

The beta subunit of tomato fruit polygalacturonase isoenzyme 1: isolation, characterization, and identification of unique structural features.

L Zheng 1, R C Heupel 1, D DellaPenna 1
PMCID: PMC160205  PMID: 1392611

Abstract

We have purified and isolated cDNAs encoding the beta subunit of tomato fruit polygalacturonase isoenzyme 1 (PG1), a cell wall protein that associates with, and apparently regulates, the catalytic PG2 polypeptides. Expression of the beta subunit is fruit specific and temporally separated from the expression of PG2 during fruit development. The 37- to 39-kD beta subunit is encoded as a 69-kD precursor protein containing a signal sequence and two propeptide domains. The mature protein is composed almost entirely of the novel 14-amino acid motif FTNYGxxGNGGxxx in which many of the phenylalanine residues are post-translationally modified. The unique structural features of the motif suggest an important role in the function of the protein and hence in the activity of PG1. The beta subunit may represent a class of bifunctional plant proteins that interact both with structural components of the cell wall and catalytic proteins to localize and/or regulate metabolic activities within the cell wall.

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Selected References

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  1. Cathala G., Savouret J. F., Mendez B., West B. L., Karin M., Martial J. A., Baxter J. D. A method for isolation of intact, translationally active ribonucleic acid. DNA. 1983;2(4):329–335. doi: 10.1089/dna.1983.2.329. [DOI] [PubMed] [Google Scholar]
  2. Dellapenna D., Kates D. S., Bennett A. B. Polygalacturonase Gene Expression in Rutgers, rin, nor, and Nr Tomato Fruits. Plant Physiol. 1987 Oct;85(2):502–507. doi: 10.1104/pp.85.2.502. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dellapenna D., Lashbrook C. C., Toenjes K., Giovannoni J. J., Fischer R. L., Bennett A. B. Polygalacturonase Isozymes and Pectin Depolymerization in Transgenic rin Tomato Fruit. Plant Physiol. 1990 Dec;94(4):1882–1886. doi: 10.1104/pp.94.4.1882. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dellapenna D., Lincoln J. E., Fischer R. L., Bennett A. B. Transcriptional Analysis of Polygalacturonase and Other Ripening Associated Genes in Rutgers, rin, nor, and Nr Tomato Fruit. Plant Physiol. 1989 Aug;90(4):1372–1377. doi: 10.1104/pp.90.4.1372. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Giovannoni J. J., DellaPenna D., Bennett A. B., Fischer R. L. Expression of a chimeric polygalacturonase gene in transgenic rin (ripening inhibitor) tomato fruit results in polyuronide degradation but not fruit softening. Plant Cell. 1989 Jan;1(1):53–63. doi: 10.1105/tpc.1.1.53. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Kraft R., Tardiff J., Krauter K. S., Leinwand L. A. Using mini-prep plasmid DNA for sequencing double stranded templates with Sequenase. Biotechniques. 1988 Jun;6(6):544-6, 549. [PubMed] [Google Scholar]
  7. Kyte J., Doolittle R. F. A simple method for displaying the hydropathic character of a protein. J Mol Biol. 1982 May 5;157(1):105–132. doi: 10.1016/0022-2836(82)90515-0. [DOI] [PubMed] [Google Scholar]
  8. Lincoln J. E., Cordes S., Read E., Fischer R. L. Regulation of gene expression by ethylene during Lycopersicon esculentum (tomato) fruit development. Proc Natl Acad Sci U S A. 1987 May;84(9):2793–2797. doi: 10.1073/pnas.84.9.2793. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Matsudaira P. Sequence from picomole quantities of proteins electroblotted onto polyvinylidene difluoride membranes. J Biol Chem. 1987 Jul 25;262(21):10035–10038. [PubMed] [Google Scholar]
  10. Moshrefi M., Luh B. S. Carbohydrate composition and electrophoretic properties of tomato polygalacturonase isoenzymes. Eur J Biochem. 1983 Oct 3;135(3):511–514. doi: 10.1111/j.1432-1033.1983.tb07681.x. [DOI] [PubMed] [Google Scholar]
  11. Osteryoung K. W., Toenjes K., Hall B., Winkler V., Bennett A. B. Analysis of tomato polygalacturonase expression in transgenic tobacco. Plant Cell. 1990 Dec;2(12):1239–1248. doi: 10.1105/tpc.2.12.1239. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Pressey R., Avants J. K. Two forms of polygalacturonase in tomatoes. Biochim Biophys Acta. 1973 Jun 6;309(2):363–369. doi: 10.1016/0005-2744(73)90035-1. [DOI] [PubMed] [Google Scholar]
  13. Pressey R. Purification and characterization of tomato polygalacturonase converter. Eur J Biochem. 1984 Oct 15;144(2):217–221. doi: 10.1111/j.1432-1033.1984.tb08452.x. [DOI] [PubMed] [Google Scholar]
  14. Themmen A. P., Tucker G. A., Grierson D. Degradation of isolated tomato cell walls by purified polygalacturonase in vitro. Plant Physiol. 1982 Jan;69(1):122–124. doi: 10.1104/pp.69.1.122. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Wallner S. J., Walker J. E. Glycosidases in Cell Wall-degrading Extracts of Ripening Tomato Fruits. Plant Physiol. 1975 Jan;55(1):94–98. doi: 10.1104/pp.55.1.94. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. von Heijne G. Patterns of amino acids near signal-sequence cleavage sites. Eur J Biochem. 1983 Jun 1;133(1):17–21. doi: 10.1111/j.1432-1033.1983.tb07424.x. [DOI] [PubMed] [Google Scholar]

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