PROSITE documentation PDOC00286Thaumatin family signature and profile
Thaumatin [1] is an intensely sweet-tasting protein (100 000 times sweeter than sucrose on a molar basis) found in berries from Thaumatococcus daniellii, an African bush. The protein consists of about 200 residues and contains 8 disulfide bonds. Several stress-induced proteins of plants have been found to be related to thaumatins. Some of these proteins are listed below.
- A maize α-amylase/trypsin inhibitor.
- Two tobacco pathogenesis-related proteins: PR-R major and minor forms, which are induced after infection with viruses.
- Salt-induced protein NP24 from tomato.
- Osmotin, a salt-induced protein from tobacco.
- Osmotin-like proteins OSML13, OSML15 and OSML81 from potato [2].
- P21, a leaf protein from soybean.
- PWIR2, a leaf protein from wheat.
- Zeamatin, a maize antifunal protein [3].
This family is also referred to as pathogenesis-related group 5 (PR5), as many thaumatin-like proteins accumulate in plants in response to infection by a pathogen and possess antifungal activity. As a signature pattern, we selected a conserved region that includes three cysteine residues known to be involved in disulfide bonds.
+----------------------------------------------------------------------+
| +-----------------+ |
| ******* | | |
xxCxxxxxxxxxxxxxxxxCxxCxxCxCxxxxxxxxxxxxxxCxxCxCxxxCxCxxCCxCxxxCxxxxxCxxxCx
| | | | | | | | || | |
+--+ +-+ | +---+ +--++-+ |
+--------------------------+
'C': conserved cysteine involved in a disulfide bond. '*': position of the pattern.
We also developed a profile that covers the whole structure [4] of thaumatin/osmotin/PR5a.
Last update:February 2008 / Text revised; profile added.
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PROSITE methods (with tools and information) covered by this documentation:
| 1 | Authors | Edens L. Heslinga L. Klok R. Ledeboer A.M. Maat J. Toonen M.Y. Visser C. Verrips C.T. |
| Title | Cloning of cDNA encoding the sweet-tasting plant protein thaumatin and its expression in Escherichia coli. | |
| Source | Gene 18:1-12(1982). | |
| PubMed ID | 7049841 |
| 2 | Authors | Zhu B. Chen T.H.H. Li P.H. |
| Title | Activation of two osmotin-like protein genes by abiotic stimuli and fungal pathogen in transgenic potato plants. | |
| Source | Plant Physiol. 108:929-937(1995). | |
| PubMed ID | 7630973 |
| 3 | Authors | Malehorn D.E. Borgmeyer J.R. Smith C.E. Shah D.M. |
| Title | Characterization and expression of an antifungal zeamatin-like protein (Zlp) gene from Zea mays. | |
| Source | Plant Physiol. 106:1471-1481(1994). | |
| PubMed ID | 7846159 |
| 4 | Authors | Koiwa H. Kato H. Nakatsu T. Oda J. Yamada Y. Sato F. |
| Title | Crystal structure of tobacco PR-5d protein at 1.8 A resolution reveals a conserved acidic cleft structure in antifungal thaumatin-like proteins. | |
| Source | J. Mol. Biol. 286:1137-1145(1999). | |
| PubMed ID | 10047487 | |
| DOI | 10.1006/jmbi.1998.2540 |
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