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SNARE motif of Bet1 Bet1 forms a complexes with GS27 (Qb), syntaxin-5 (Qa) and Sec22B (R-SNARE) or GS28 (Qb), syntaxin-5 (Qa) and Ykt6 (R-SNARE). These complexes regulates the early secretory pathway of eukaryotic cells at the level of the transport from endoplasmic reticulum (ER) to the ER-Golgi intermediate compartment (ERGIC) and from ERGIC to the cis-Golgi, respectively. Bet1 is a member of the Qc subgroup of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, which consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complexes mediate membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",