4ROA

1.90A resolution structure of SRPN2 (S358W) from Anopheles gambiae

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.172 

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This is version 1.2 of the entry. See complete history. 

Literature

Structural and Inhibitory Effects of Hinge Loop Mutagenesis in Serpin-2 from the Malaria Vector Anopheles gambiae.

Zhang, X., Meekins, D.A., An, C., Zolkiewski, M., Battaile, K.P., Kanost, M.R., Lovell, S., Michel, K.

(2015) J.Biol.Chem. 290: 2946-2956

  • DOI: 10.1074/jbc.M114.625665
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • Serpin-2 (SRPN2) is a key negative regulator of the melanization response in the malaria vector Anopheles gambiae. SRPN2 irreversibly inhibits clip domain serine proteinase 9 (CLIPB9), which functions in a serine proteinase cascade culminating in the ...

    Serpin-2 (SRPN2) is a key negative regulator of the melanization response in the malaria vector Anopheles gambiae. SRPN2 irreversibly inhibits clip domain serine proteinase 9 (CLIPB9), which functions in a serine proteinase cascade culminating in the activation of prophenoloxidase and melanization. Silencing of SRPN2 in A. gambiae results in spontaneous melanization and decreased life span and is therefore a promising target for vector control. The previously determined structure of SRPN2 revealed a partial insertion of the hinge region of the reactive center loop (RCL) into β sheet A. This partial hinge insertion participates in heparin-linked activation in other serpins, notably antithrombin III. SRPN2 does not contain a heparin binding site, and any possible mechanistic function of the hinge insertion was previously unknown. To investigate the function of the SRPN2 hinge insertion, we developed three SRPN2 variants in which the hinge regions are either constitutively expelled or inserted and analyzed their structure, thermostability, and inhibitory activity. We determined that constitutive hinge expulsion resulted in a 2.7-fold increase in the rate of CLIPB9Xa inhibition, which is significantly lower than previous observations of allosteric serpin activation. Furthermore, we determined that stable insertion of the hinge region did not appreciably decrease the accessibility of the RCL to CLIPB9. Together, these results indicate that the partial hinge insertion in SRPN2 does not participate in the allosteric activation observed in other serpins and instead represents a molecular trade-off between RCL accessibility and efficient formation of an inhibitory complex with the cognate proteinase.

    Organizational Affiliation: 

    From the Division of Biology, Kansas State University, Manhattan, Kansas 66506.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Serpin 2
A
397Anopheles gambiaeMutation(s): 1 
Gene Names: SRPN2
Find proteins for Q005N3 (Anopheles gambiae)
Go to UniProtKB:  Q005N3
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.172 
  • Space Group: P 63
Unit Cell:
Length (Å)Angle (°)
a = 96.946α = 90.00
b = 96.946β = 90.00
c = 78.569γ = 120.00
Software Package:
Software NamePurpose
Aimlessdata scaling
PDB_EXTRACTdata extraction
PHENIXrefinement
XDSdata reduction
JDirectordata collection
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-12-24
    Type: Initial release
  • Version 1.1: 2015-02-11
    Type: Database references
  • Version 1.2: 2017-11-22
    Type: Refinement description