PDBsum entry 2mlu

Antimicrobial protein

PDB id: 2mlu

Contents

Protein chain

30 a.a.

PDB id:

2mlu

Name:

Antimicrobial protein

Title:

Structure of the antimicrobial peptide lsbb in dpc micelles

Structure:

Lsbb. Chain: a. Engineered: yes

Source:

Synthetic: yes. Lactococcus lactis subsp. Lactis. Organism_taxid: 1360

NMR struc:

20 models

Authors:

P.Kristiansen,K.Ovchinnikov,D.Diep

Key ref:

K.V.Ovchinnikov et al. (2014). Defining the structure and receptor binding domain of the leaderless bacteriocin LsbB. J Biol Chem, 289, 23838-23845. PubMed id: 24993828 DOI: 10.1074/jbc.M114.579698

Date:

05-Mar-14 Release date: 16-Jul-14

Protein chain

Q7X2B5  (Q7X2B5_LACLL) -  LsbB from Lactococcus lactis subsp. lactis

Seq: 30 a.a.

Struc: 30 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.M114.579698

J Biol Chem 289:23838-23845 (2014)

PubMed id: 24993828

Defining the structure and receptor binding domain of the leaderless bacteriocin LsbB.

K.V.Ovchinnikov, P.E.Kristiansen, G.Uzelac, L.Topisirovic, M.Kojic, J.Nissen-Meyer, I.F.Nes, D.B.Diep.

ABSTRACT

LsbB is a class II leaderless lactococcal bacteriocin of 30 amino acids. In the present work, the structure and function relationship of LsbB was assessed. Structure determination by NMR spectroscopy showed that LsbB has an N-terminal α-helix, whereas the C-terminal of the molecule remains unstructured. To define the receptor binding domain of LsbB, a competition assay was performed in which a systematic collection of truncated peptides of various lengths covering different parts of LsbB was used to inhibit the antimicrobial activity of LsbB. The results indicate that the outmost eight-amino acid sequence at the C-terminal end is likely to contain the receptor binding domain because only truncated fragments from this region could antagonize the antimicrobial activity of LsbB. Furthermore, alanine substitution revealed that the tryptophan in position 25 (Trp(25)) is crucial for the blocking activity of the truncated peptides, as well as for the antimicrobial activity of the full-length bacteriocin. LsbB shares significant sequence homology with five other leaderless bacteriocins, especially at their C-terminal halves where all contain a conserved KXXXGXXPWE motif, suggesting that they might recognize the same receptor as LsbB. This notion was supported by the fact that truncated peptides with sequences derived from the C-terminal regions of two LsbB-related bacteriocins inhibited the activity of LsbB, in the same manner as found with the truncated version of LsbB. Taken together, these structure-function studies provide strong evidence that the receptor-binding parts of LsbB and sequence-related bacteriocins are located in their C-terminal halves.