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Colicins U and Y inhibit growth of Escherichia coli strains via recognition of conserved OmpA extracellular loop 1.

Authors :
Bosák J
Micenková L
Doležalová M
Šmajs D
Source :
International journal of medical microbiology : IJMM [Int J Med Microbiol] 2016 Nov; Vol. 306 (7), pp. 486-494. Date of Electronic Publication: 2016 Aug 02.
Publication Year :
2016

Abstract

Interactions of colicins U and Y with the OmpA (Outer membrane protein A) receptor molecule were studied using site-directed mutagenesis and colicin binding assay. A systematic mutagenesis of the colicin-susceptible OmpA sequence from Escherichia coli (OmpA <subscript>EC</subscript> ) to the colicin-resistant OmpA sequence from Serratia marcescens (OmpA <subscript>SM</subscript> ) was performed in regions corresponding to extracellular OmpA loops 1-4. Susceptibility to colicins U and Y was significantly affected by the OmpA mutation in loop 1. As with functional analysis, a decrease in binding capacity of His-tagged colicin U was found for recombinant OmpA with a mutated segment in loop 1 compared to control OmpA <subscript>EC</subscript> . To verify the importance of the identified amino acid residues in OmpA loop 1, we introduced loop 1 from OmpA <subscript>EC</subscript> into OmpA <subscript>SM</subscript> , which resulted in the substantial increase of susceptibility to colicins U and Y. In addition, colicins U and Y were tested against a panel of 118 bacteriocin non-producing strains of four Escherichia species, including E. coli (39 strains), E. fergusonii (10 strains), E. hermannii (42 strains), and E. vulneris (27 strains). A majority (82%) of E. coli strains was susceptible to colicins U and Y. Interestingly, colicins U and Y also inhibited all of the 30 tested multidrug-resistant E. coli O25b-ST131 isolates. These findings, together with the fact that OmpA loop 1 is important for bacterial virulence and is evolutionary conserved, offer the potential of using colicins U and Y as specific anti-OmpA loop 1 directed antibacterial proteins.<br /> (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Details

Language :
English
ISSN :
1618-0607
Volume :
306
Issue :
7
Database :
MEDLINE
Journal :
International journal of medical microbiology : IJMM
Publication Type :
Academic Journal
Accession number :
27510856
Full Text :
https://doi.org/10.1016/j.ijmm.2016.07.002