Domain

Synaptotagmin, SMP domain (IPR039010)

Short name: Synaptotagmin_SMP

Overlapping homologous superfamilies

None.

Domain relationships

Description

SMP is a proposed lipid-binding module, ie a synaptotagmin-like mitochondrial-lipid-binding domain found in eukaryotes. The SMP domain has a beta-barrel structure like protein modules in the tubular-lipid-binding (TULIP) superfamily. It dimerises to form an approximately 90-Angstrom-long cylinder traversed by a channel lined entirely with hydrophobic residues. The following two C2 domains then form arched structures flexibly linked to the SMP domain. The SMP domain is a lipid-binding domain that links the ER with other lipid bilayer-membranes within the cell [PMID: 24847877].

This entry represents the SMP domain found in plant synaptotagmins [PMID: 27811083] and extended synaptotagmins from metazoa. The extended synaptotagmins transport glycerolipids between the two bilayers via their lipid-harboring SMP domains and Ca2 + regulates their membrane tethering and lipid transport function [PMID: 28363589].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
Pfam