7A1R

Crystal structure of the C2B domain of Trypanosoma brucei extended synaptotagmin (E-Syt)

Summary for 7A1R

• Entry DOI: 10.2210/pdb7a1r/pdb
• Descriptor: Synaptotagmin, CALCIUM ION, CHLORIDE ION, ... (6 entities in total)
• Functional Keywords: c2 domain, extended synaptotagmin, lipid transfer, trypanosoma, lipid binding protein
• Biological source: Trypanosoma brucei equiperdum
• Total number of polymer chains: 2
• Total formula weight: 30969.26

Authors

Dong, G. (deposition date: 2020-08-13, release date: 2021-06-02, Last modification date: 2024-05-15)

Primary citation

Stepinac, E.,Landrein, N.,Skwarzynska, D.,Wojcik, P.,Lesigang, J.,Lucic, I.,He, C.Y.,Bonhivers, M.,Robinson, D.R.,Dong, G.
Structural studies of the shortest extended synaptotagmin with only two C2 domains from Trypanosoma brucei .
Iscience, 24:102422-102422, 2021

PubMed Abstract: Extended synaptotagmins (E-Syts) localize at membrane contact sites between the endoplasmic reticulum (ER) and the plasma membrane to mediate inter-membrane lipid transfer and control plasma membrane lipid homeostasis. All known E-Syts contain an N-terminal transmembrane (TM) hairpin, a central synaptotagmin-like mitochondrial lipid-binding protein (SMP) domain, and three or five C2 domains at their C termini. Here we report an uncharacterized E-Syt from the protist parasite , namely, TbE-Syt. TbE-Syt contains only two C2 domains (C2A and C2B), making it the shortest E-Syt known by now. We determined a 1.5-Å-resolution crystal structure of TbE-Syt-C2B and revealed that it binds lipids via both Ca- and PI(4,5)P-dependent means. In contrast, TbE-Syt-C2A lacks the Ca-binding site but may still interact with lipids via a basic surface patch. Our studies suggest a mechanism for how TbE-Syt tethers the ER membrane tightly to the plasma membrane to transfer lipids between the two organelles.

PubMed: 33997700
DOI: 10.1016/j.isci.2021.102422

Experimental method

X-RAY DIFFRACTION (1.5 Å)