3SWH

Munc13-1, MUN domain, C-terminal module

Summary for 3SWH

• Entry DOI: 10.2210/pdb3swh/pdb
• Descriptor: Protein unc-13 homolog A (2 entities in total)
• Functional Keywords: alpha helical, neurotransmitter release, snare motif, exocytosis
• Biological source: Rattus norvegicus (rat); More
• Cellular location: Cytoplasm: Q62768
• Total number of polymer chains: 2
• Total formula weight: 77473.04

Authors

Tomchick, D.R.,Rizo, J.,Li, W. (deposition date: 2011-07-13, release date: 2011-11-02, Last modification date: 2024-02-28)

Primary citation

Li, W.,Ma, C.,Guan, R.,Xu, Y.,Tomchick, D.R.,Rizo, J.
The Crystal Structure of a Munc13 C-terminal Module Exhibits a Remarkable Similarity to Vesicle Tethering Factors.
Structure, 19:1443-1455, 2011

PubMed Abstract: Unc13/Munc13s play a crucial function in neurotransmitter release through their MUN domain, which mediates the transition from the Syntaxin-1/Munc18-1 complex to the SNARE complex. The MUN domain was suggested to be related to tethering factors, but no MUN-domain structure is available to experimentally validate this notion and address key unresolved questions about the interactions and minimal structural unit required for Unc13/Munc13 function. Here we identify an autonomously folded module within the MUN domain (MUN-CD) and show that its crystal structure is remarkably similar to several tethering factors. We also show that the activity in promoting the Syntaxin-1/Munc18-1 to SNARE complex transition is strongly impaired in MUN-CD. These results show that MUN domains and tethering factors indeed belong to the same family and may have a common role in membrane trafficking. We propose a model whereby the MUN-CD module is central for Munc13 function but full activity requires adjacent sequences.

PubMed: 22000513
DOI: 10.1016/j.str.2011.07.012

Experimental method

X-RAY DIFFRACTION (2.65 Å)