1MQS: Crystal Structure Of Sly1p In Complex With An N-terminal Peptide Of Sed5p

Cytosolic Sec1/munc18-like proteins (SM proteins) are recruited to membrane fusion sites by interaction with syntaxin-type SNARE proteins, constituting indispensable positive regulators of intracellular membrane fusion. Here we present the crystal structure of the yeast SM protein Sly1p in complex with a short N-terminal peptide derived from the Golgi-resident syntaxin Sed5p. Sly1p folds, similarly to neuronal Sec1, into a three-domain arch-shaped assembly, and Sed5p interacts in a helical conformation predominantly with domain I of Sly1p on the opposite site of the nSec1/syntaxin-1-binding site. Sequence conservation of the major interactions suggests that homologues of Sly1p as well as the paralogous Vps45p group bind their respective syntaxins in the same way. Furthermore, we present indirect evidence that nSec1 might be able to contact syntaxin 1 in a similar fashion. The observed Sly1p-Sed5p interaction mode therefore indicates how SM proteins can stay associated with the assembling fusion machinery in order to participate in late fusion steps.
PDB ID: 1MQSDownload
MMDB ID: 21248
PDB Deposition Date: 2002/9/17
Updated in MMDB: 2002/12
Experimental Method:
x-ray diffraction
Resolution: 3  Å
Source Organism:
Similar Structures:
Biological Unit for 1MQS: dimeric; determined by author and by software (PISA)
Molecular Components in 1MQS
Label Count Molecule
Proteins (2 molecules)
Sly1 Protein(Gene symbol: SLY1)
Molecule annotation
Integral Membrane Protein Sed5(Gene symbol: SED5)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB