NMR solution structure of the carnobacteriocin B2 immunity protein

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

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NMR Solution Structure of ImB2, a Protein Conferring Immunity to Antimicrobial Activity of the Type IIa Bacteriocin, Carnobacteriocin B2

Sprules, T.Kawulka, K.E.Vederas, J.C.

(2004) Biochemistry 43: 11740-11749

  • DOI: https://doi.org/10.1021/bi048854+
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Bacteriocins produced by lactic acid bacteria are potent antimicrobial compounds which are active against closely related bacteria. Producer strains are protected against the effects of their cognate bacteriocins by immunity proteins that are located on the same genetic locus and are coexpressed with the gene encoding the bacteriocin. Several structures are available for class IIa bacteriocins; however, to date, no structures are available for the corresponding immunity proteins. We report here the NMR solution structure of the 111-amino acid immunity protein for carnobacteriocin B2 (ImB2). ImB2 folds into a globular domain in aqueous solution which contains an antiparallel four-helix bundle. Extensive packing by hydrophobic side chains in adjacent helices forms the core of the protein. The C-terminus, containing a fifth helix and an extended strand, is held against the four-helix bundle by hydrophobic interactions with helices 3 and 4. Most of the charged and polar residues in the protein face the solvent. Helix 3 is well-defined to residue 55, and a stretch of nascent helix followed by an unstructured loop joins it to helix 4. No interaction is observed between ImB2 and either carnobacteriocin B2 (CbnB2) or its precursor. Protection from the action of CbnB2 is only observed when ImB2 is expressed within the cell. The loop between helices 3 and 4, and a hydrophobic pocket which it partially masks, may be important for interaction with membrane receptors responsible for sensitivity to class IIa bacteriocins.

  • Organizational Affiliation

    Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
carnobacteriocin B2 immunity protein111Carnobacterium maltaromaticumMutation(s): 0 
Gene Names: cbiB2
Find proteins for P38582 (Carnobacterium maltaromaticum)
Explore P38582 
Go to UniProtKB:  P38582
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP38582
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-09-28
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-03-02
    Changes: Database references, Derived calculations
  • Version 1.4: 2024-05-22
    Changes: Data collection