Transcription is the first of several steps of DNA based gene expression in which a particular segment of DNA is copied into RNA by the enzyme RNA polymerase.
Amanita phalloides, commonly known as the death cap, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Widely distributed across Europe, but now sprouting in other parts of the world, A. phalloides forms ectomycorrhizas with various broadleaved trees. In some cases, the death cap has been introduced to new regions with the cultivation of non-native species of oak, chestnut, and pine. The large fruiting bodies (mushrooms) appear in summer and autumn; the caps are generally greenish in colour with a white stipe and gills. Cap colour is variable, including white forms, and thus not a reliable identifier.
The name destroying angel applies to several similar, closely related species of deadly all-white mushrooms in the genus Amanita. They are Amanita bisporigera and A. ocreata in eastern and western North America, and A. virosa in Europe. Another very similar species, A. verna or fool's mushroom, was first described in France.
alpha-Amanitin or α-amanitin is a cyclic peptide of eight amino acids. It is possibly the most deadly of all the amatoxins, toxins found in several species of the mushroom genus Amanita, one being the death cap as well as the destroying angel, a complex of similar species, principally A. virosa and A. bisporigera. It is also found in the mushrooms Galerina marginata and Conocybe filaris. The oral LD50 of amanitin is approximately 0.1 mg/kg for rats.
Amanita virosa, commonly known in Europe as the destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in Europe, A. virosa associates with various deciduous and coniferous trees. The large fruiting bodies appear in summer and autumn; the caps, stipes and gills are all white in colour.
RNA polymerase II is a multiprotein complex that transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNAP enzymes found in the nucleus of eukaryotic cells. A 550 kDa complex of 12 subunits, RNAP II is the most studied type of RNA polymerase. A wide range of transcription factors are required for it to bind to upstream gene promoters and begin transcription.
Amatoxin is the collective name of a subgroup of at least eight related toxic compounds found in several genera of poisonous mushrooms, most notably the death cap and several other members of the genus Amanita, as well as some Conocybe, Galerina and Lepiota mushroom species. Amatoxins are lethal in even small doses, as little as half a mushroom. Unlike many ingested poisons, they cannot be destroyed by heat without destroying the mushrooms beyond edibility first, so cooking the poisonous mushrooms does not diminish their lethality.
Amanin is a cyclic peptide. It is one of the amatoxins, all of which are found in several members of the mushroom genus Amanita.
Galerina marginata, known colloquially as the Funeral Bell or the Deadly Skullcap, is a species of poisonous fungus in the family Hymenogastraceae of the order Agaricales. Prior to 2001, the species G. autumnalis, G. oregonensis, G. unicolor, and G. venenata were thought to be separate due to differences in habitat and the viscidity of their caps, but phylogenetic analysis showed that they are all the same species.
Amanita ocreata, commonly known as the death angel, destroying angel, angel of death or more precisely western North American destroying angel, is a deadly poisonous basidiomycete fungus, one of many in the genus Amanita. Occurring in the Pacific Northwest and California floristic provinces of North America, A. ocreata associates with oak trees. The large fruiting bodies generally appear in spring; the cap may be white or ochre and often develops a brownish centre, while the stipe, ring, gill and volva are all white.
beta-Amanitin or β-amanitin is a cyclic peptide comprising eight amino acids. It is part of a group of toxins called amatoxins, which can be found in several mushrooms belonging to the genus Amanita. Some examples are the death cap and members of the destroying angel complex, which includes A. virosa and A. bisporigera. Due to the presence of α-amanitin, β-amanitin, γ-amanitin and ε-amanitin these mushrooms are highly lethal to human beings.
gamma-Amanitin or γ-amanitin is a cyclic peptide of eight amino acids. It is an amatoxin, a group of toxins isolated from and found in several members of the mushroom genus Amanita, one being the death cap as well as the destroying angel, a complex of similar species, principally A. virosa and A. bisporigera. The compound is highly toxic, inhibits RNA polymerase II, disrupts synthesis of mRNA, and can be fatal.
Amanullin is a cyclic peptide. It is an amatoxin, all of which are found in several members of the mushroom genus Amanita. The oral LD50 of amanullin is approximately 20 mg/kg in mice; however, it is non-toxic in humans.
Promanullin is a cyclic nonribosomal peptide. It is an amatoxin, all of which are found in the mushroom genus Amanita.
epsilon-Amanitin or ε-amanitin is a cyclic peptide. It is an amatoxin, all of which are found in several members of the mushroom genus Amanita. The oral LD50 of ε-amanitin is approximately 0.1 mg/kg.
Amanullinic acid is a cyclic nonribosomal peptide. It is an amatoxin, all of which are found in several members of the mushroom genus Amanita. Amanullinic acid is relatively non-toxic( oral LD50 >20 mg/kg in mice).
Galerina sulciceps is a dangerously toxic species of fungus in the family Strophariaceae, of the order Agaricales. It is distributed in tropical Indonesia and India, but has reportedly been found fruiting in European greenhouses on occasion. More toxic than the deathcap, G. sulciceps has been shown to contain the toxins alpha- (α-), beta- (β-) and gamma- (γ-) amanitin; a series of poisonings in Indonesia in the 1930s resulted in 14 deaths from the consumption of this species. It has a typical "little brown mushroom" appearance, with few obvious external characteristics to help distinguish it from many other similar nondescript brown species. The fruit bodies of the fungus are tawny to ochre, deepening to reddish-brown at the base of the stem. The gills are well-separated, and there is no ring present on the stem.
Amanita bisporigera is a deadly poisonous species of fungus in the family Amanitaceae. It is commonly known as the eastern North American destroying angel or just as the destroying angel, although the fungus shares this latter name with three other lethal white Amanita species, A. ocreata, A. verna and A. virosa. The fruit bodies are found on the ground in mixed coniferous and deciduous forests of eastern North America south to Mexico, but are rare in western North America; the fungus has also been found in pine plantations in Colombia. The mushroom has a smooth white cap that can reach up to 10 cm (4 in) across, and a stipe, up to 14 cm (5.5 in) long by 1.8 cm (0.7 in) thick, that has a delicate white skirt-like ring near the top. The bulbous stipe base is covered with a membranous sac-like volva. The white gills are free from attachment to the stalk and crowded closely together. As the species name suggests, A. bisporigera typically bears two spores on the basidia, although this characteristic is not as immutable as was once thought.
Amanita exitialis, also known as the Guangzhou destroying angel, is a mushroom of the large genus Amanita. It is distributed in eastern Asia, and probably also in India where it has been misidentified as A. verna. Deadly poisonous, it is a member of section Phalloideae and related to the death cap A. phalloides. The fruit bodies (mushrooms) are white, small to medium-sized with caps up to 7 cm (2.8 in) in diameter, a somewhat friable ring and a firm volva. Unlike most agaric mushrooms which typically have four-spored basidia, the basidia of A. exitialis are almost entirely two-spored. Eight people were fatally poisoned in China after consuming the mushroom in 2000, and another 20 have been fatally poisoned since that incident. Molecular analysis shows that the species has a close phylogenetic relationship with three other toxic white Amanitas: A. subjunquillea var. alba, A. virosa and A. bisporigera.
Toxalbumins are toxic plant proteins that disable ribosomes and thereby inhibit protein synthesis, producing severe cytotoxic effects in multiple organ systems. They are dimers held together by a disulfide bond and comprise a lectin part which binds to the cell membrane and enables the toxin part to gain access to the cell contents. Toxalbumins are similar in structure to the toxins found in cholera, tetanus, diphtheria and botulinum; and their physiological and toxic properties are similar to those of viperine snake venom.
