Complete sequence of low-copy-number plasmid MccC7-H22 of probiotic Escherichia coli H22 and the prevalence of mcc genes among human E. coli

MccE Provides Resistance to Protein Synthesis Inhibitor Microcin C by Acetylating the Processed Form of the Antibiotic

“…Thus, plasmids with each of the amber mutations tested behaved as the original mccE Ϫ plasmid (above) and therefore destroyed the mccE function. The correct mccE start site must therefore be located upstream of the introduced amber codons and therefore matches the site proposed by Smajs et al (18) overlapping with the mccD gene.…”

“…We resequenced part of the mcc gene cluster of the Russian isolate between mccD and mccE and determined that the original sequence of Fomenko et al (8) contained an error. The corrected sequence matches that of Smajs et al (18). The correction of the sequence led to an ambiguity in the assignment of the mccE start codon, which was originally proposed to begin with an ATG (7,8) located ϳ190 bp downstream of the last codon of mccD (Fig.…”

“…The reason(s) for this difference remained unknown. We observed that although both plasmids could be introduced into either host with high efficiency, the mutant, mccE (17,18) revealed a 1-bp difference (an insertion of a C:G base pair, indicated by a downward arrow in Fig. 3) between the earlier reported sequences of mcc operons carried on plasmids isolated in Spain (7) and Russia (8) and a more recent isolate (Fig.…”

“…3). Smajs et al (18) proposed that translation of MccE is initiated much more upstream, from an ATG codon overlapping with mccD (Fig. 3).…”

Novel Colicin F Y of Yersinia frederiksenii Inhibits Pathogenic Yersinia Strains via YiuR-Mediated Reception, TonB Import, and Cell Membrane Pore Formation

“…In general, colicins are directed against both commensal and pathogenic E. coli strains, except for colicin Js, which is active against enteroinvasive E. coli, just as Shigella strains (28,65). Although the precise general role of colicins in the human gut is unknown, there is increasing evidence for bacteriocin-enhanced E. coli colonization of the gastrointestinal tract (21), for the role of colicins in bacterial virulence (e.g., colicin E1 [62]), and for colicin's role in the probiotic phenotype of E. coli strains (14,63).…”