Crystal structure of an intramolecular chaperone mediating triple-beta-helix folding.
Nat Struct Mol Biol
; 17(2): 210-5, 2010 Feb.
Article
em En
| MEDLINE
| ID: mdl-20118935
Protein folding is often mediated by molecular chaperones. Recently, a novel class of intramolecular chaperones has been identified in tailspike proteins of evolutionarily distant viruses, which require a C-terminal chaperone for correct folding. The highly homologous chaperone domains are interchangeable between pre-proteins and release themselves after protein folding. Here we report the crystal structures of two intramolecular chaperone domains in either the released or the pre-cleaved form, revealing the role of the chaperone domain in the formation of a triple-beta-helix fold. Tentacle-like protrusions enclose the polypeptide chains of the pre-protein during the folding process. After the assembly, a sensory mechanism for correctly folded beta-helices triggers a serine-lysine catalytic dyad to autoproteolytically release the mature protein. Sequence analysis shows a conservation of the intramolecular chaperones in functionally unrelated proteins sharing beta-helices as a common structural motif.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas Virais
/
Fagos Bacilares
/
Colífagos
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Chaperonas Moleculares
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article