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PDBsum entry 4nkh

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protein Protein-protein interface(s) links
Ligase PDB id
4nkh

 

 

 

 

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Contents
Protein chains
(+ 0 more) 236 a.a.
PDB id:
4nkh
Name: Ligase
Title: Crystal structure of ssph1 lrr domain
Structure: E3 ubiquitin-protein ligase ssph1. Chain: a, b, c, d, e, f. Fragment: lrr domains, unp residues 161-398. Synonym: salmonella secreted protein h1, secreted effector protein ssph1. Engineered: yes
Source: Salmonella enterica subsp. Enterica serovar typhimurium. Organism_taxid: 588858. Strain: 14028s. Gene: ssph1, stm14_1483. Expressed in: escherichia coli.
Resolution:
2.75Å     R-factor:   0.245     R-free:   0.280
Authors: A.F.A.Keszei,T.Xiaojing,C.Mccormick,E.Zeqiraj,J.R.Rohde,M.Tyers, F.Sicheri
Key ref: A.F.Keszei et al. (2014). Structure of an SspH1-PKN1 complex reveals the basis for host substrate recognition and mechanism of activation for a bacterial E3 ubiquitin ligase. Mol Cell Biol, 34, 362-373. PubMed id: 24248594 DOI: 10.1128/MCB.01360-13
Date:
12-Nov-13     Release date:   11-Dec-13    
PROCHECK
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 Headers
 References

Protein chains
Pfam   ArchSchema ?
D0ZVG2  (SSPH1_SALT1) -  E3 ubiquitin-protein ligase SspH1 from Salmonella typhimurium (strain 14028s / SGSC 2262)
Seq:
Struc:
 
Seq:
Struc:
700 a.a.
236 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.2.3.2.27  - RING-type E3 ubiquitin transferase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N6- ubiquitinyl-[acceptor protein]-L-lysine

 

 
DOI no: 10.1128/MCB.01360-13 Mol Cell Biol 34:362-373 (2014)
PubMed id: 24248594  
 
 
Structure of an SspH1-PKN1 complex reveals the basis for host substrate recognition and mechanism of activation for a bacterial E3 ubiquitin ligase.
A.F.Keszei, X.Tang, C.McCormick, E.Zeqiraj, J.R.Rohde, M.Tyers, F.Sicheri.
 
  ABSTRACT  
 
IpaH proteins are bacterium-specific E3 enzymes that function as type three secretion system (T3SS) effectors in Salmonella, Shigella, and other Gram-negative bacteria. IpaH enzymes recruit host substrates for ubiquitination via a leucine-rich repeat (LRR) domain, which can inhibit the catalytic domain in the absence of substrate. The basis for substrate recognition and the alleviation of autoinhibition upon substrate binding is unknown. Here, we report the X-ray structure of Salmonella SspH1 in complex with human PKN1. The LRR domain of SspH1 interacts specifically with the HR1b coiled-coil subdomain of PKN1 in a manner that sterically displaces the catalytic domain from the LRR domain, thereby activating catalytic function. SspH1 catalyzes the ubiquitination and proteasome-dependent degradation of PKN1 in cells, which attenuates androgen receptor responsiveness but not NF-κB activity. These regulatory features are conserved in other IpaH-substrate interactions. Our results explain the mechanism whereby substrate recognition and enzyme autoregulation are coupled in this class of bacterial ubiquitin ligases.
 

 

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