4KDW

Crystal structure of a bacterial immunoglobulin-like domain from the M. primoryensis ice-binding adhesin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.165 
  • R-Value Work: 0.130 
  • R-Value Observed: 0.132 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Role of Ca(2+) in folding the tandem beta-sandwich extender domains of a bacterial ice-binding adhesin.

Guo, S.Garnham, C.P.Karunan Partha, S.Campbell, R.L.Allingham, J.S.Davies, P.L.

(2013) FEBS J 280: 5919-5932

  • DOI: 10.1111/febs.12518
  • Primary Citation of Related Structures:  
    4KDV, 4KDW

  • PubMed Abstract: 
  • A Ca(2+) -dependent 1.5-MDa antifreeze protein present in an Antarctic Gram-negative bacterium, Marinomonas primoryensis (MpAFP), has recently been reassessed as an ice-binding adhesin. The non-ice-binding region II (RII), one of five distinct domains in MpAFP, constitutes ~ 90% of the protein ...

    A Ca(2+) -dependent 1.5-MDa antifreeze protein present in an Antarctic Gram-negative bacterium, Marinomonas primoryensis (MpAFP), has recently been reassessed as an ice-binding adhesin. The non-ice-binding region II (RII), one of five distinct domains in MpAFP, constitutes ~ 90% of the protein. RII consists of ~ 120 tandem copies of an identical 104-residue sequence. We used the Protein Homology/analogy Recognition Engine server to define the boundaries of a single 104-residue RII construct (RII monomer). CD demonstrated that Ca(2+) is required for RII monomer folding, and that the monomer is fully structured at a Ca(2+) /protein molar ratio of 10 : 1. The crystal structure of the RII monomer was solved to a resolution of 1.35 Å by single-wavelength anomalous dispersion and molecular replacement methods with Ca(2+) as the heavy atom to obtain phase information. The RII monomer folds as a Ca(2+) -bound immunoglobulin-like β-sandwich. Ca(2+) ions are coordinated at the interfaces between each RII monomer and its symmetry-related molecules, suggesting that these ions may be involved in the stabilization of the tandemly repeated RII. We hypothesize that > 600 Ca(2+) ions help to rigidify the chain of 104-residue repeats in order to project the ice-binding domain of MpAFP away from the bacterial cell surface. The proposed role of RII is to help the strictly aerobic bacterium bind surface ice in an Antarctic lake for better access to oxygen and nutrients. This work may give insights into other bacterial proteins that resemble MpAFP, especially those of the large repeats-in-toxin family that have been characterized as adhesins exported via the type I secretion pathway.


    Organizational Affiliation

    The Protein Function Discovery Group, Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Antifreeze proteinA123Marinomonas primoryensisMutation(s): 0 
Gene Names: MpAFP
Find proteins for A1YIY3 (Marinomonas primoryensis)
Explore A1YIY3 
Go to UniProtKB:  A1YIY3
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.35 Å
  • R-Value Free: 0.165 
  • R-Value Work: 0.130 
  • R-Value Observed: 0.132 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 25.64α = 97.02
b = 28.62β = 112.93
c = 32.25γ = 96.88
Software Package:
Software NamePurpose
JBluIce-EPICSdata collection
PHASERphasing
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-10-02
    Type: Initial release
  • Version 1.1: 2013-11-13
    Changes: Database references
  • Version 1.2: 2014-05-07
    Changes: Other