6VZD

N-terminal domain of mouse surfactant protein B (K46E/R51E mutant) with bound lipid

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.88 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history. 


Literature

Mechanism of Lamellar Body Formation by Lung Surfactant Protein B.

Sever, N., Milicic, G., Bodnar, N.O., Wu, X., Rapoport, T.A.

(2020) Mol Cell 

  • DOI: 10.1016/j.molcel.2020.10.042
  • Primary Citation of Related Structures:  
    6VYN, 6VZ0, 6VZE, 6VZD, 6W1B

  • 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 secret ...

    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.

    Organizational Affiliation: 

    Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA. Electronic address: tom_rapoport@hms.harvard.edu.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Pulmonary surfactant-associated protein BA, B, C, E87Mus musculusMutation(s): 2 
Gene Names: Sftpb, Sftp3
Find proteins for P50405 (Mus musculus)
Explore P50405 
Go to UniProtKB:  P50405
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
RXY
Query on RXY
Download Ideal Coordinates CCD File 
A, B, E
(7Z,19R,22R)-25-amino-22-hydroxy-16,22-dioxo-17,21,23-trioxa-22lambda~5~-phosphapentacos-7-en-19-yl (9Z)-octadec-9-enoate
C39 H74 N O8 P
RAMNOXDFBNFSFC-AVWHJSSGSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.793α = 90
b = 66.124β = 97.37
c = 59.62γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
Cootmodel building
XDSdata scaling
PHENIXphasing
XDSdata reduction

Structure Validation

View Full Validation Report


View more in-depth experimental data

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Howard Hughes Medical Institute (HHMI)United States--

Revision History 

  • Version 1.0: 2020-11-25
    Type: Initial release
  • Version 1.1: 2020-12-02
    Changes: Database references
  • Version 1.2: 2020-12-09
    Changes: Database references