The SNARE complex from yeast is partially unstructured on the membrane.
Structure
; 16(7): 1138-46, 2008 Jul.
Article
em En
| MEDLINE
| ID: mdl-18611386
ABSTRACT
Molecular recognition between cognate SNAREs leads to the formation of a four-helix bundle, which facilitates vesicle docking and membrane fusion. For a SNARE system involved in trafficking in yeast, target membrane (t-) SNARE Sso1p and vesicle associated (v-) SNARE Snc2p contribute one SNARE motif each, whereas another t-SNARE (Sec9) donates two N-terminal and C-terminal SNARE motifs (SN1 and SN2) to the helical bundle. By use of EPR, it is found that SN2 has a tendency to be uncoiled, leaving a significant population of the SNARE complexes to be partially unstructured on the membrane. In sharp contrast, SN2 is fully engaged in the four-helix bundle when removed from the membrane, showing that the membrane is the main destabilizing factor. Helix-breaking proline mutations in SN2 did not affect the rate of docking but reduced the rate of lipid mixing significantly, indicating that SN2 plays an essential role in activating the transition from docking to fusion.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Saccharomyces cerevisiae
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Proteínas SNARE
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Proteínas Qc-SNARE
/
Fusão de Membrana
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article