<p>Thaumatin [<cite idref="PUB00001747"/>] is an intensely sweet-tasting protein, 100,000 times sweeter than sucrose on a molar basis [<cite idref="PUB00001747"/>] found in berries from <taxon tax_id="4621">Thaumatococcus daniellii</taxon>, a tropical flowering plant known as Katemfe, it is induced by attack by viroids, which are single-stranded unencapsulated RNA molecules that do not code for protein.</p><p>Thaumatin consists of about 200 residues and contains 8 disulphide bonds. Like other PR proteins, thaumatin is predicted to have a mainly beta structure, with a high content of beta-turns and little helix [<cite idref="PUB00001747"/>]. Several stress-induced proteins of plants have been found to be related to thaumatins: </p><p> <ul><li>A maize alpha-amylase/trypsin inhibitor</li> <li>Two tobacco pathogenesis-related proteins: PR-R major and minor forms,which are induced after infection with viruses </li> <li>Salt-induced protein NP24 from tomato</li> <li>Osmotin, a salt-induced protein from tobacco [<cite idref="PUB00043682"/>]</li> <li>Osmotin-like proteins OSML13, OSML15 and OSML81 from potato [<cite idref="PUB00004582"/>]</li> <li>P21, a leaf protein from soybean</li> <li>PWIR2, a leaf protein from wheat [<cite idref="PUB00004543"/>]</li> <li>Zeamatin, a maize antifungal protein [<cite idref="PUB00004580"/>]</li></ul> </p><p>This protein 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 [<cite idref="PUB00004556"/>]. The proteins are involved in systematically acquired resistance and stress responses in plants, although their precise role is unknown [<cite idref="PUB00004556"/>].</p><p>This entry represents a conserved site that includes three cysteine residues known to be involved in disulphide bonds.</p> Thaumatin, conserved site