7Y5Q

Structure of 1:1 PAPP-A.STC2 complex(half map)


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.80 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

Structural insights into the covalent regulation of PAPP-A activity by proMBP and STC2.

Zhong, Q.Chu, H.Wang, G.Zhang, C.Li, R.Guo, F.Meng, X.Lei, X.Zhou, Y.Ren, R.Tao, L.Li, N.Gao, N.Wei, Y.Qiao, J.Hang, J.

(2022) Cell Discov 8: 137-137

  • DOI: https://doi.org/10.1038/s41421-022-00502-2
  • Primary Citation of Related Structures:  
    7Y5N, 7Y5Q, 8HGG, 8HGH

  • PubMed Abstract: 

    Originally discovered in the circulation of pregnant women as a protein secreted by placental trophoblasts, the metalloprotease pregnancy-associated plasma protein A (PAPP-A) is also widely expressed by many other tissues. It cleaves insulin-like growth factor-binding proteins (IGFBPs) to increase the bioavailability of IGFs and plays essential roles in multiple growth-promoting processes. While the vast majority of the circulatory PAPP-A in pregnancy is proteolytically inactive due to covalent inhibition by proform of eosinophil major basic protein (proMBP), the activity of PAPP-A can also be covalently inhibited by another less characterized modulator, stanniocalcin-2 (STC2). However, the structural basis of PAPP-A proteolysis and the mechanistic differences between these two modulators are poorly understood. Here we present two cryo-EM structures of endogenous purified PAPP-A in complex with either proMBP or STC2. Both modulators form 2:2 heterotetramer with PAPP-A and establish extensive interactions with multiple domains of PAPP-A that are distal to the catalytic cleft. This exosite-binding property results in a steric hindrance to prevent the binding and cleavage of IGFBPs, while the IGFBP linker region-derived peptides harboring the cleavage sites are no longer sensitive to the modulator treatment. Functional investigation into proMBP-mediated PAPP-A regulation in selective intrauterine growth restriction (sIUGR) pregnancy elucidates that PAPP-A and proMBP collaboratively regulate extravillous trophoblast invasion and the consequent fetal growth. Collectively, our work reveals a novel covalent exosite-competitive inhibition mechanism of PAPP-A and its regulatory effect on placental function.


  • Organizational Affiliation

    Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Maltose/maltodextrin-binding periplasmic protein,Pappalysin-1
A, B
1,944Escherichia coli K-12Homo sapiens
This entity is chimeric
Mutation(s): 0 
Gene Names: malEb4034JW3994PAPPA
EC: 3.4.24.79
UniProt & NIH Common Fund Data Resources
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Explore P0AEX9 
Go to UniProtKB:  P0AEX9
Find proteins for Q13219 (Homo sapiens)
Explore Q13219 
Go to UniProtKB:  Q13219
PHAROS:  Q13219
GTEx:  ENSG00000182752 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupsP0AEX9Q13219
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Stanniocalcin-2302Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for O76061 (Homo sapiens)
Explore O76061 
Go to UniProtKB:  O76061
PHAROS:  O76061
GTEx:  ENSG00000113739 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO76061
Sequence Annotations
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONRELION3.1.2

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China82071658

Revision History  (Full details and data files)

  • Version 1.0: 2023-01-11
    Type: Initial release
  • Version 1.1: 2024-11-06
    Changes: Data collection, Structure summary