Biology:Bacteriocin IId

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Bacteriocin_IId
PDB 1o82 EBI.jpg
x-ray structure of bacteriocin as-48 at ph 4.5. sulphate bound form
Identifiers
SymbolBacteriocin_IId
PfamPF09221
InterProIPR009086
SCOP21o82 / SCOPe / SUPFAM
TCDB1.C.28

Bacteriocin AS-48 is a cyclic peptide antibiotic produced by the eubacteria Enterococcus faecalis (Streptococcus faecalis) that shows a broad antimicrobial spectrum against both Gram-positive and Gram-negative bacteria. Bacteriocin AS-48 is encoded by the pheromone-responsive plasmid pMB2, and acts on the plasma membrane in which it opens pores leading to ion leakage and cell death.[1] The globular structure of bacteriocin AS-48 is composed of five alpha helices enclosing a hydrophobic core. The mammalian NK-lysin effector protein of T and natural killer cells has a similar structure, though it lacks sequence homology with bacteriocins AS-48.

Bacteriocin uses components of the mannose phosphotransferase system (man-PTS)[2] of susceptible cells as target/receptor. The immunity protein LciA forms a strong complex with the receptor proteins and the bacteriocin, thereby preventing cells from being killed. The complex between LciA and the man-PTS components (IIAB, IIC, and IID) appears to involve an on–off type mechanism that allows complex formation only in the presence of bacteriocin; otherwise no complexes were observed between LciA and the receptor proteins.[3]

References

This article incorporates text from the public domain Pfam and InterPro: IPR009086