Nucleotide sequence of the colicin B activity gene cba: consensus pentapeptide among TonB-dependent colicins and receptors

Schramm, Edgar; Mende, Julia; Braun, Volkmar; Kamp, Roza Maria

doi:10.1128/jb.169.7.3350-3357.1987

Cited by 163 publications

(87 citation statements)

References 44 publications

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“…The entire colicin B and M gene region was sequenced for 60 E. coli strains selected to represent the diversity present among the strains encoding these genes. Primers for sequencing were designed as needed using published colicin B and M gene sequences (Johnson et al, 2006a;Köck et al, 1987;Ö lschläger & Braun, 1987;Schramm et al, 1987Schramm et al, , 1988 (Supplementary Table S1). DNA fragments were amplified using the PCR conditions described above, and PCR products were purified with the DNA purification reagent ExoSAP-IT (USB).…”

Section: Methodsmentioning

confidence: 99%

“…DNA and amino acid sequence variation in colicins B and M Several previously published colicin B and M sequences were included in the analyses: the colicin region of the plasmid pAPEC-O1-ColBM, and separately published sequences for cmi, cma, cbi and cba (Köck et al, 1987;Ö lschläger & Braun, 1987;Schramm et al, 1987Schramm et al, , 1988. Sequence variation statistics and codon-based Z-tests for selection were performed for each colicin gene (Table 2).…”

Section: Gene Structure Of Colicin Bm Plasmidsmentioning

confidence: 99%

“…The expression of most colicins is induced under conditions of stress via the SOS response (Lu & Chak, 1996), and studies indicate that expression of both colicin B and colicin M is regulated at the same SOS box located upstream of the B activity gene (Gillor et al, 2008b;Köck et al, 1987;Ö lschläger et al, 1984). Colicin B has a molecular mass of 54.7 kDa (Schramm et al, 1987), while colicin M is the smallest known colicin, with a molecular mass of 29.5 kDa (Köck et al, 1987). The receptors exploited by colicins B and M to enter a sensitive cell are the siderophore receptors FepA and FhuA, respectively.…”

Section: Introductionmentioning

confidence: 99%

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Evolution of colicin BM plasmids: the loss of the colicin B activity gene

Christenson

Gordon

2009

Microbiology

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Colicins, a class of antimicrobial compounds produced by bacteria, are thought to be important mediators of intra-and interspecific interactions, and are a significant factor in maintaining microbial diversity. Colicins B and M are among the most common colicins produced by Escherichia coli, and are usually encoded adjacently on the same plasmid. In this study, the characterization of a collection of E. coli isolated from Australian vertebrates revealed that a significant fraction of colicin BM strains lack an intact colicin B activity gene. The colicin B and M gene region was sequenced in 60 strains and it was found (with one exception) that all plasmids lacking an intact colicin B activity gene have an identical colicin gene structure, possessing a complete colicin B immunity gene and a 130 bp remnant of the B activity gene. A phylogenetic analysis of the colicin M and B operons and characterization of the plasmids suggested that ColBM plasmids with a truncated B activity gene have evolved on at least three separate occasions. Colicin B immunity was found to be non-functional in strains that have lost colicin B activity, and colicin M was still produced despite the absence of the SOS box believed to regulate its production in colicin BM strains. The presence of a remnant of the microcin V operon next to the truncated colicin B activity gene indicated that these plasmids evolved as a consequence of gene transfer between colicin BM and microcin V plasmids. We suggest that these transfer events most likely involved the transfer of some microcin V genes and associated virulence factors onto ColBM plasmids.

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Section: Methodsmentioning

confidence: 99%

Section: Gene Structure Of Colicin Bm Plasmidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Evolution of colicin BM plasmids: the loss of the colicin B activity gene

Christenson

Gordon

2009

Microbiology

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“…The N-terminal translocation domains of group B colicins contain a pentapeptide motif, called the ' TonB box', which is also found in the FepA and BtuB receptor proteins (Schramm et al, 1987). Mutations in the TonB box of group B colicins (or in their receptors) reduce colicin uptake (Mende & Braun, 1990), and can be suppressed by mutations in TonB (Braun, 1995).…”

Section: Introductionmentioning

confidence: 99%

Identification of residues in the putative TolA box which are essential for the toxicity of the endonuclease toxin colicin E9

et al. 1997

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E colicins are plasmid-coded, protein antibiotics which bind to the BtuB outer membrane receptor of Escheriehia coli cells and are then translocated either to the outer surface of the cytoplasmic membrane in the case of the pore-forming colicin El, or to the cytoplasm in the case of the enzymic colicins E2-E9. Translocation has been proposed to be dependent on a putative TolA box; a pentapeptide (DGSGW) located in the N-terminal39 residues of several Toldependent colicins. In this study, site-directed mutagenesis was used to change each of the residues of the putative TolA box of coljcin E9 to alanines.In the case of the two glycine residues, the resulting mutant proteins were indistinguishable from the native colicin E9 protein in a biological assay; whereas the other three residues when mutated to alanines resulted in a complete loss of biological activity. Mutagenesis of two serine residues flanking the putative TolA box, Ser34 and Sera, to alanines did not abolish the biological activity of the mutant colicin E9, although the zones of growth inhibition were hazy and slow to form. The size of the zone of inhibition was significantly smaller than the control in the case of the Ser40Ala mutant. The ColE9/lm9 complex was isolated from the three biologically inactive TolA box alanine mutants. In competition assays all three mutant protein complexes were capable of protecting sensitive E. coli cells against killing by the native ColE9/lm9 complex. On removal of the lm9 protein from the three mutant ColE9/lm9 complexes, all three mutant colicins exhibited DNase activity. These results confirm the importance of the putative TolA box in the biological activity of colicin E9, and suggest that the TolA box has a role in the translocation of colicin E9.

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“…The Pst protein is devoid of a signal peptide, indicating a Sec-independent mode of export. Pesticin carries a highly conserved N-terminal pentapeptide typical of all TonB-dependent bacteriocins (Schramm et al, 1987) that is identical to that of colicin B: Asp-Thr-Met-Val-Val (aa 3-7) (Fig. 2).…”

Section: Pesticin Activity Protein Pstmentioning

confidence: 99%

Structural and functional organization of the Yersinia pestis bacteriocin pesticin gene cluster

Rakin¹,

Boolgakowa

Heesemann³

1996

Microbiology

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The primary structure of a 2671 bp DNA fragment between the pla gene (encoding plasminogen activator) and the origin of replication of the wild-type Yersinia pestis plasmid pYP358 was determined. Two ORFs of 1074 and 426 bp with opposite transcription polarities were identified on both strands. They encode a 357 aa pesticin activity protein (Pst) and a 141 aa pesticin immunity polypeptide (Pim). A GC-rich palindromic structure located between pst and pim can form a hairpin loop and serve as a rho-independent transcription terminator sequence for both genes. The site for the interaction with the LexA repressor of the SOS system was found in another palindromic structure preceding the pst structural gene. A deduced 399 kDa Pst polypeptide is devoid of a signal peptide, indicating a Sec-independent mode of export. Pst carries a pentapeptide typical of TonB-dependent colicins (TonB box) that is necessary for the interaction with the yersiniabactidpesticin receptor and for active energyldependent transport through the outer membrane. The substitution of the last five C-terminal amino acids did not significantly influence the bactericidal activity of the truncated pesticin. The pesticin lost its ability to kill sensitive bacteria and to bind to a pesticin receptor after deletion of the last 57 C-terminal amino acids. A deduced 16 kDa Pim protein has an Nterminal hydrophobic amino acid stretch with features typical of prokaryotic signal peptides. Pim is a slightly hydrophilic protein with a basic pl. The immunity protein was localized in the periplasmic space and in the outermembrane fraction after its overexpression under the polymerase T7 promoter. Several other ORFs were identified on the sequenced 2671 bp fragment, but none of them seemed to encode a typical lysis peptide, which is necessary for the release of the pesticin. In the promoter region and in the regions preceding and following the pst operon, the DNA sequence has high (> 70%) identity with other colicin genes. The DNA sequence located 284 bp upstream of the pim gene showed more than 90% similarity to antisense RNA I of the ColEl replicon. This defined the location of the pYP358 origin of ColE1-type replication.

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Nucleotide sequence of the colicin B activity gene cba: consensus pentapeptide among TonB-dependent colicins and receptors

Cited by 163 publications

References 44 publications

Evolution of colicin BM plasmids: the loss of the colicin B activity gene

Evolution of colicin BM plasmids: the loss of the colicin B activity gene

Identification of residues in the putative TolA box which are essential for the toxicity of the endonuclease toxin colicin E9

Structural and functional organization of the Yersinia pestis bacteriocin pesticin gene cluster

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