6Y9B

Cryo-EM structure of trimeric human STEAP1 bound to three Fab120.545 fragments


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.97 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Cryo-EM structure and potential enzymatic function of human six-transmembrane epithelial antigen of the prostate 1.

Oosterheert, W.Gros, P.

(2020) J Biol Chem 

  • DOI: 10.1074/jbc.RA120.013690
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Six-transmembrane epithelial antigen of the prostate 1 (STEAP1) is an integral membrane protein that is highly upregulated on the cell surface of several human cancers, making it a promising therapeutic target to manage these diseases. It shares sequ ...

    Six-transmembrane epithelial antigen of the prostate 1 (STEAP1) is an integral membrane protein that is highly upregulated on the cell surface of several human cancers, making it a promising therapeutic target to manage these diseases. It shares sequence homology with three enzymes (STEAP2-4) that catalyze the NADPH-dependent reduction of iron(III). However, STEAP1 lacks an intracellular NADPH-binding domain and does not exhibit cellular ferric-reductase activity. Thus, both the molecular function of STEAP1 and its role in cancer progression remain elusive. Here, we present a ~3.0 Å cryo-EM structure of trimeric human STEAP1 bound to three antigen-binding fragments (Fabs) of the clinically used antibody mAb120.545. The structure disclosed that STEAP1 adopts a reductase-like conformation and interacts with the Fabs through its extracellular helices. Enzymatic assays in human cells revealed that STEAP1 promotes iron(III) reduction when fused to the intracellular NADPH-binding domain of its family member STEAP4, suggesting that STEAP1 functions as a ferric reductase in STEAP hetero-trimers. Our work provides a foundation for deciphering the molecular mechanisms of STEAP1 and may be instrumental in the design of new therapeutic strategies to target STEAP1 in cancer.


    Organizational Affiliation

    Utrecht University, Netherlands.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Metalloreductase STEAP1
A, B, C
380Homo sapiensMutation(s): 0 
Gene Names: STEAP1PRSS24STEAP
EC: 1.16.1
Find proteins for Q9UHE8 (Homo sapiens)
Go to UniProtKB:  Q9UHE8
NIH Common Fund Data Resources
PHAROS  Q9UHE8

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Fab120.545 light chain
L, M, N
220Mus musculusMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.

Find similar proteins by: Sequence  |  Structure

Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Fab120.545 heavy chain
H, I, J
238Mus musculusMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A, B, C
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
XP4
Query on XP4

Download CCD File 
A, B, C
1,2-DIMYRISTOYL-SN-GLYCERO-3-PHOSPHATE
C31 H60 O8 P
OZSITQMWYBNPMW-GDLZYMKVSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.97 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Netherlands Organisation for Scientific Research (NWO)Netherlands731.015.201

Revision History 

  • Version 1.0: 2020-05-20
    Type: Initial release
  • Version 1.1: 2020-05-27
    Changes: Database references