Biomaterial Database

Conformation of the mushroom toxin beta-amanitin in the crystalline state. 1978

E C Kostansek, and W N Lipscomb, and R R Yocum, and W E Thiessen

A single crystal X-ray diffraction analysis of beta-amanitin, a bicyclic octapeptide toxin isolated from the poisonous mushroom Amanita phalloides, shows that the molecule has distinct regions of hydrophilic and hydrophobic residues and two 18-membered rings. The study confirms the proposed chemical sequence and the configuration of the residues. All eight peptide groups are in the trans conformation. Four intramolecular hydrogen bonds, two strong and two weak, occur in the structure. The toxin cocrystallizes with seven water and three ethanol molecules and participates in an extensive hydrogen-bonding network. The crystal structure was solved by direct methods. The space group is P2(1)2(1)2(1), and unit cell dimensions are a = 14.004(3), b = 14.943(3), and c = 30.794(7) A.

UI	MeSH Term	Description	Entries
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D003460	Crystallization	The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Crystalline Polymorphs,Polymorphism, Crystallization,Crystal Growth,Polymorphic Crystals,Crystal, Polymorphic,Crystalline Polymorph,Crystallization Polymorphism,Crystallization Polymorphisms,Crystals, Polymorphic,Growth, Crystal,Polymorph, Crystalline,Polymorphic Crystal,Polymorphisms, Crystallization,Polymorphs, Crystalline
D000546	Amanitins	Cyclic peptides extracted from carpophores of various mushroom species. They are potent inhibitors of RNA polymerases in most eukaryotic species, blocking the production of mRNA and protein synthesis. These peptides are important in the study of transcription. Alpha-amanitin is the main toxin from the species Amanitia phalloides, poisonous if ingested by humans or animals.	Amanitin
D014961	X-Ray Diffraction	The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Xray Diffraction,Diffraction, X-Ray,Diffraction, Xray,Diffractions, X-Ray,Diffractions, Xray,X Ray Diffraction,X-Ray Diffractions,Xray Diffractions