7MBK

N-terminal domain of mouse surfactant protein B, 6W mutant

7MBK の概要

• エントリーDOI: 10.2210/pdb7mbk/pdb
• 関連するPDBエントリー: 6vyn 6vz0 6vzd 6vze 6w1b
• 分子名称: Pulmonary surfactant-associated protein B (2 entities in total)
• 機能のキーワード: surfactant protein
• 由来する生物種: Mus musculus (Mouse)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 20859.94

構造登録者

Milicic, G.,Rapoport, T.A. (登録日: 2021-03-31, 公開日: 2021-04-14, 最終更新日: 2024-11-06)

主引用文献

Sever, N.,Milicic, G.,Bodnar, N.O.,Wu, X.,Rapoport, T.A.
Mechanism of Lamellar Body Formation by Lung Surfactant Protein B.
Mol.Cell, 81:49-66.e8, 2021

PubMed Abstract: Breathing depends on pulmonary surfactant, a mixture of phospholipids and proteins, secreted by alveolar type II cells. Surfactant requires lamellar bodies (LBs), organelles containing densely packed concentric membrane layers, for storage and secretion. LB biogenesis remains mysterious but requires surfactant protein B (SP-B), which is synthesized as a precursor (pre-proSP-B) that is cleaved during trafficking into three related proteins. Here, we elucidate the functions and cooperation of these proteins in LB formation. We show that the N-terminal domain of proSP-B is a phospholipid-binding and -transfer protein whose activities are required for proSP-B export from the endoplasmic reticulum (ER) and sorting to LBs, the conversion of proSP-B into lipoprotein particles, and neonatal viability in mice. The C-terminal domain facilitates ER export of proSP-B. The mature middle domain, generated after proteolytic cleavage of proSP-B, generates the striking membrane layers characteristic of LBs. Together, our results lead to a mechanistic model of LB biogenesis.

PubMed: 33242393
DOI: 10.1016/j.molcel.2020.10.042

実験手法

X-RAY DIFFRACTION (2.17 Å)