7Y10

Crystal structure of AtSFH5-Sec14 in complex with DPPA

7Y10 の概要

• エントリーDOI: 10.2210/pdb7y10/pdb
• 分子名称: Phosphatidylinositol/phosphatidylcholine transfer protein SFH5, 1,2-DIPALMITOYL-SN-GLYCERO-3-PHOSPHATE, NICKEL (II) ION, ... (4 entities in total)
• 機能のキーワード: sec14p homolog protein (sfh), arabidopsis thaliana, chloroplast, phosphatidic acid (pa), lipid transport
• 由来する生物種: Arabidopsis thaliana (mouse-ear cress)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70768.13

構造登録者

Lu, Y.Q.,Wang, X.Q.,Luo, Z.P.,Wu, J.W. (登録日: 2022-06-06, 公開日: 2023-05-31, 最終更新日: 2023-11-29)

主引用文献

Yao, H.Y.,Lu, Y.Q.,Yang, X.L.,Wang, X.Q.,Luo, Z.,Lin, D.L.,Wu, J.W.,Xue, H.W.
Arabidopsis Sec14 proteins (SFH5 and SFH7) mediate interorganelle transport of phosphatidic acid and regulate chloroplast development.
Proc.Natl.Acad.Sci.USA, 120:e2221637120-e2221637120, 2023

PubMed Abstract: Lipids establish the specialized thylakoid membrane of chloroplast in eukaryotic photosynthetic organisms, while the molecular basis of lipid transfer from other organelles to chloroplast remains further elucidation. Here we revealed the structural basis of Sec14 homology proteins AtSFH5 and AtSFH7 in transferring phosphatidic acid (PA) from endoplasmic reticulum (ER) to chloroplast, and whose function in regulating the lipid composition of chloroplast and thylakoid development. AtSFH5 and AtSFH7 localize at both ER and chloroplast, whose deficiency resulted in an abnormal chloroplast structure and a decreased thickness of stacked thylakoid membranes. We demonstrated that AtSFH5, but not yeast and human Sec14 proteins, could specifically recognize and transfer PA in vitro. Crystal structures of the AtSFH5-Sec14 domain in complex with L-α-phosphatidic acid (L-α-PA) and 1,2-dipalmitoyl-sn-glycero-3-phosphate (DPPA) revealed that two PA ligands nestled in the central cavity with different configurations, elucidating the specific binding mode of PA to AtSFH5, different from the reported phosphatidylethanolamine (PE)/phosphatidylcholine (PC)/phosphatidylinositol (PI) binding modes. Quantitative lipidomic analysis of chloroplast lipids showed that PA and monogalactosyldiacylglycerol (MGDG), particularly the C18 fatty acids at -2 position in MGDG were significantly decreased, indicating a disrupted ER-to-plastid (chloroplast) lipid transfer, under deficiency of AtSFH5 and AtSFH7. Our studies identified the role and elucidated the structural basis of plant SFH proteins in transferring PA between organelles, and suggested a model for ER-chloroplast interorganelle phospholipid transport from inherent ER to chloroplast derived from endosymbiosis of a cyanobacteriumproviding a mechanism involved in the adaptive evolution of cellular plastids.

PubMed: 36716376
DOI: 10.1073/pnas.2221637120

実験手法

X-RAY DIFFRACTION (2.1 Å)