Biological Assembly 1  

 3D View: Structure | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 88.45 kDa 
• Atom Count: 3098 
• Residue Count: 420 
• Unique protein chains: 2

6M49

cryo-EM structure of Scap/Insig complex in the present of 25-hydroxyl cholesterol.

• DOI: 10.2210/pdb6M49/pdb
• EMDataResource: EMD-30074

• Classification: MEMBRANE PROTEIN
• Organism(s): Homo sapiens
• Expression System: Homo sapiens
• Mutation(s): Yes 


• Deposited: 2020-03-06 Released: 2021-01-20 
• Deposition Author(s): Yan, R., Cao, P., Song, W., Qian, H., Du, X., Coates, H.W., Zhao, X., Li, Y., Gao, S., Gong, X., Liu, X., Sui, J., Lei, J., Yang, H., Brown, A.J., Zhou, Q., Yan, C., Yan, N.
• Funding Organization(s): Ministry of Science and Technology (MoST, China)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.70 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

A structure of human Scap bound to Insig-2 suggests how their interaction is regulated by sterols.

Yan, R., Cao, P., Song, W., Qian, H., Du, X., Coates, H.W., Zhao, X., Li, Y., Gao, S., Gong, X., Liu, X., Sui, J., Lei, J., Yang, H., Brown, A.J., Zhou, Q., Yan, C., Yan, N.

(2021) Science 

• PubMed: 33446483 
• DOI: 10.1126/science.abb2224
• Primary Citation of Related Structures:  
  6M49


• PubMed Abstract: 
  

The SREBP pathway controls cellular homeostasis of sterols. The key players in this pathway, Scap and Insig-1/2, are membrane-embedded sterol sensors. 25-hydroxycholesterol (25HC)-dependent association of Scap and Insigs acts as the master switch for the SREBP pathway. Here, we present cryo-EM analysis of the human Scap and Insig-2 complex in the presence of 25HC, with the transmembrane (TM) domains determined at an average resolution of 3.7 Å. The sterol sensing domain (SSD) in Scap and all six TMs in Insig-2 were resolved. A 25HC molecule is sandwiched between the S4-S6 segments in Scap and TMs 3/4 in Insig-2 in the luminal leaflet of the membrane. Unwinding of the middle of the Scap-S4 segment is crucial for 25HC binding and Insig association.

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Organizational Affiliation: 

Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA. [e-mail] [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Insulin-induced gene 2 protein	A	225	Homo sapiens	Mutation(s): 3  Gene Names: INSIG2
Find proteins for Q9Y5U4 (Homo sapiens) Explore Q9Y5U4  Go to UniProtKB:  Q9Y5U4
NIH Common Fund Data Resources
PHAROS:  Q9Y5U4 GTEx:  ENSG00000125629

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Sterol regulatory element-binding protein cleavage-activating protein,Sterol regulatory element-binding protein cleavage-activating protein	B	572	Homo sapiens	Mutation(s): 0  Gene Names: SCAP
Find proteins for Q12770 (Homo sapiens) Explore Q12770  Go to UniProtKB:  Q12770
NIH Common Fund Data Resources
PHAROS:  Q12770 GTEx:  ENSG00000114650

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HC3	A	25-HYDROXYCHOLESTEROL C27 H46 O2 INBGSXNNRGWLJU-ZHHJOTBYSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.70 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2020-03-06 
• Released Date: 2021-01-20 
Deposition Author(s): Yan, R., Cao, P., Song, W., Qian, H., Du, X., Coates, H.W., Zhao, X., Li, Y., Gao, S., Gong, X., Liu, X., Sui, J., Lei, J., Yang, H., Brown, A.J., Zhou, Q., Yan, C., Yan, N.

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Funding Organization	Location	Grant Number
Ministry of Science and Technology (MoST, China)	China	--

Revision History 

• Version 1.0: 2021-01-20
  Type: Initial release
  
• Version 1.1: 2021-01-27
  Changes: Database references