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PDBsum entry 3lh4

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protein ligands links
Hydrolase inhibitor PDB id
3lh4
Jmol
Contents
Protein chain
115 a.a. *
Ligands
SO4
GOL
Waters ×106
* Residue conservation analysis
PDB id:
3lh4
Name: Hydrolase inhibitor
Title: Crystal structure of sialostatin l2
Structure: Secreted cystatin. Chain: a. Fragment: unp residues 19-132. Engineered: yes
Source: Ixodes scapularis. Blacklegged tick, shoulder tick. Organism_taxid: 6945. Gene: iscw_iscw018602. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
1.80Å     R-factor:   0.174     R-free:   0.196
Authors: J.F.Andersen,M.Kotsyfakis,J.Salat,H.Horka
Key ref: M.Kotsyfakis et al. (2010). The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model. Mol Microbiol, 77, 456-470. PubMed id: 20545851
Date:
21-Jan-10     Release date:   29-Sep-10    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
B7PKZ1  (B7PKZ1_IXOSC) -  Secreted cystatin
Seq:
Struc:
132 a.a.
115 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biochemical function     cysteine-type endopeptidase inhibitor activity     1 term  

 

 
Mol Microbiol 77:456-470 (2010)
PubMed id: 20545851  
 
 
The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model.
M.Kotsyfakis, H.Horka, J.Salat, J.F.Andersen.
 
  ABSTRACT  
 
Summary We have previously demonstrated that two salivary cysteine protease inhibitors from the Borrelia burgdorferi (Lyme disease) vector Ixodes scapularis -namely sialostatins L and L2- play an important role in tick biology, as demonstrated by the fact that silencing of both sialostatins in tandem results in severe feeding defects. Here we show that sialostatin L2 -but not sialostatin L- facilitates the growth of Borrelia burgdorferi in murine skin. To examine the structural basis underlying these differential effects of the two sialostatins, we have determined the crystal structures of both sialostatin L and L2. This is the first structural analysis of cystatins from an invertebrate source. Sialostatin L2 crystallizes as a monomer with an 'unusual' conformation of the N-terminus, while sialostatin L crystallizes as a domain-swapped dimer with an N-terminal conformation similar to other cystatins. Deletion of the 'unusual' N-terminal five residues of sialostatin L2 results in marked changes in its selectivity, suggesting that this region is a particularly important determinant of the biochemical activity of sialostatin L2. Collectively, our results reveal the structure of two tick salivary components that facilitate vector blood feeding and that one of them also supports pathogen transmission to the vertebrate host.
 

 

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