4n59

Publication Abstract from PubMed

The colicin-like bacteriocins are potent protein antibiotics that have evolved to efficiently cross the outer membrane of Gram-negative bacteria by parasitising nutrient uptake systems. We have structurally characterised the colicin M-like bacteriocin, pectocin M2, which is active against strains of Pectobacterium spp. This unusual bacteriocin lacks the intrinsically unstructured translocation domain that usually mediates translocation of these bacteriocins across the outer membrane, containing only a single globular ferredoxin domain connected to its cytotoxic domain by a flexible alpha-helix, which allows it to adopt two distinct conformations in solution. The ferredoxin domain of pectocin M2 is homologous to plant ferredoxins and allows pectocin M2 to parasitize a system utilised by Pectobacterium to obtain iron during infection of plants. Furthermore, we identify a novel ferredoxin-containing bacteriocin pectocin P, which possesses a cytotoxic domain homologous to lysozyme, illustrating that the ferredoxin domain acts as a generic delivery module for cytotoxic domains in Pectobacterium.

Structure of the atypical bacteriocin pectocin M2 implies a novel mechanism of protein uptake.,Grinter R, Josts I, Zeth K, Roszak AW, McCaughey LC, Cogdell RJ, Milner JJ, Kelly SM, Byron O, Walker D Mol Microbiol. 2014 May 28. doi: 10.1111/mmi.12655. PMID:24865810^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.