Abstract
Seventeen full-length cDNAs encoding pectin methyl esterase I (PME I) have been isolated from the filamentous fungus Aspergillus aculeatus by expression cloning in yeast. Yeast colonies expressing functional PME I were identified on agar plates containing highly esterified pectin, and a cDNA encoding PME I was isolated. The deduced amino acid sequence of PME I is highly similar (74% identity) to the PME from Aspergillus niger. A full-length cDNA encoding PME I was cloned into an Aspergillus expression vector and transformed into Aspergillus oryzae for heterologous expression, purification and characterization of the recombinant enzyme. The recombinant PME I had a molecular mass of 36.2 kDa, an isoelectric point of pH 3.8, a pH optimum of 4.6 and a temperature optimum of 45 degrees C. The authentic PME I was purified from A. aculeatus culture supernatant and subjected to amino acid sequencing. The peptide sequences covered 138 amino acid residues and were in complete agreement with the deduced PME I sequence. Both recombinant and authentic PME I were glycosylated, but the composition of the glycan moieties was different. PME I was able to remove 75-85% of the methyl groups in highly methylated pectin, and it did not remove acetyl groups from acetylated polysaccharides. When the enzyme was added together with polygalacturonases to pectin, a rapid depolymerization was observed. By comparison, polygalacturonases alone showed a very limited degradation of the methylated substrate. This demonstrates that PME I acts in synergy with polygalacturonases in the degradation of plant cell wall pectin.
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- Becker D. M., Guarente L. High-efficiency transformation of yeast by electroporation. Methods Enzymol. 1991;194:182–187. doi: 10.1016/0076-6879(91)94015-5. [DOI] [PubMed] [Google Scholar]
- Carpita N. C., Gibeaut D. M. Structural models of primary cell walls in flowering plants: consistency of molecular structure with the physical properties of the walls during growth. Plant J. 1993 Jan;3(1):1–30. doi: 10.1111/j.1365-313x.1993.tb00007.x. [DOI] [PubMed] [Google Scholar]
- Christgau S., Kauppinen S., Vind J., Kofod L. V., Dalbøge H. Expression cloning, purification and characterization of a beta-1,4-mannanase from Aspergillus aculeatus. Biochem Mol Biol Int. 1994 Aug;33(5):917–925. [PubMed] [Google Scholar]
- Christgau S., Sandal T., Kofod L. V., Dalbøge H. Expression cloning, purification and characterization of a beta-1,4-galactanase from Aspergillus aculeatus. Curr Genet. 1995 Jan;27(2):135–141. doi: 10.1007/BF00313427. [DOI] [PubMed] [Google Scholar]
- Dalbøge H., Heldt-Hansen H. P. A novel method for efficient expression cloning of fungal enzyme genes. Mol Gen Genet. 1994 May 10;243(3):253–260. doi: 10.1007/BF00301060. [DOI] [PubMed] [Google Scholar]
- Devereux J., Haeberli P., Smithies O. A comprehensive set of sequence analysis programs for the VAX. Nucleic Acids Res. 1984 Jan 11;12(1 Pt 1):387–395. doi: 10.1093/nar/12.1part1.387. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kauppinen S., Christgau S., Kofod L. V., Halkier T., Dörreich K., Dalbøge H. Molecular cloning and characterization of a rhamnogalacturonan acetylesterase from Aspergillus aculeatus. Synergism between rhamnogalacturonan degrading enzymes. J Biol Chem. 1995 Nov 10;270(45):27172–27178. doi: 10.1074/jbc.270.45.27172. [DOI] [PubMed] [Google Scholar]
- Khanh N. Q., Ruttkowski E., Leidinger K., Albrecht H., Gottschalk M. Characterization and expression of a genomic pectin methyl esterase-encoding gene in Aspergillus niger. Gene. 1991 Sep 30;106(1):71–77. doi: 10.1016/0378-1119(91)90567-u. [DOI] [PubMed] [Google Scholar]
- Kobata A. Structures and functions of the sugar chains of glycoproteins. Eur J Biochem. 1992 Oct 15;209(2):483–501. doi: 10.1111/j.1432-1033.1992.tb17313.x. [DOI] [PubMed] [Google Scholar]
- Kofod L. V., Kauppinen S., Christgau S., Andersen L. N., Heldt-Hansen H. P., Dörreich K., Dalbøge H. Cloning and characterization of two structurally and functionally divergent rhamnogalacturonases from Aspergillus aculeatus. J Biol Chem. 1994 Nov 18;269(46):29182–29189. [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Laurent F., Kotoujansky A., Labesse G., Bertheau Y. Characterization and overexpression of the pem gene encoding pectin methylesterase of Erwinia chrysanthemi strain 3937. Gene. 1993 Sep 6;131(1):17–25. doi: 10.1016/0378-1119(93)90664-o. [DOI] [PubMed] [Google Scholar]
- Lim Y. M., Chung M. C. Isolation and characterization of pectin methylesterase from papaya. Arch Biochem Biophys. 1993 Nov 15;307(1):15–20. doi: 10.1006/abbi.1993.1553. [DOI] [PubMed] [Google Scholar]
- Markovic O., Jörnvall H. Disulfide bridges in tomato pectinesterase: variations from pectinesterases of other species; conservation of possible active site segments. Protein Sci. 1992 Oct;1(10):1288–1292. doi: 10.1002/pro.5560011007. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sherman F. Getting started with yeast. Methods Enzymol. 1991;194:3–21. doi: 10.1016/0076-6879(91)94004-v. [DOI] [PubMed] [Google Scholar]
- Spök A., Stubenrauch G., Schörgendorfer K., Schwab H. Molecular cloning and sequencing of a pectinesterase gene from Pseudomonas solanacearum. J Gen Microbiol. 1991 Jan;137(1):131–140. doi: 10.1099/00221287-137-1-131. [DOI] [PubMed] [Google Scholar]
- Strathern J. N., Higgins D. R. Recovery of plasmids from yeast into Escherichia coli: shuttle vectors. Methods Enzymol. 1991;194:319–329. doi: 10.1016/0076-6879(91)94024-7. [DOI] [PubMed] [Google Scholar]
- Teerlink T., Hennekes M. W., van Leeuwen P. A., Houdijk A. Rapid determination of glutamine in biological samples by high-performance liquid chromatography. Clin Chim Acta. 1993 Sep 30;218(2):159–168. doi: 10.1016/0009-8981(93)90180-c. [DOI] [PubMed] [Google Scholar]
- van den Hazel H. B., Kielland-Brandt M. C., Winther J. R. Autoactivation of proteinase A initiates activation of yeast vacuolar zymogens. Eur J Biochem. 1992 Jul 1;207(1):277–283. doi: 10.1111/j.1432-1033.1992.tb17048.x. [DOI] [PubMed] [Google Scholar]
- von Heijne G. A new method for predicting signal sequence cleavage sites. Nucleic Acids Res. 1986 Jun 11;14(11):4683–4690. doi: 10.1093/nar/14.11.4683. [DOI] [PMC free article] [PubMed] [Google Scholar]