Structural Analysis of Plasmid pLQ510 from Moraxella catarrhalis E22

Liu, Lixia; Hansen, Eric J.

doi:10.1006/plas.1999.1411

Cited by 7 publications

(7 citation statements)

References 26 publications

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“…Plasmid-specific sequences were identified in a single genome (BC7), underscoring the paucity of naturally occurring plasmids reported in the M. catarrhalis literature ([23,24] and reviewed in [25]).…”

Section: Resultsmentioning

confidence: 99%

“…Interestingly, the BC7 plasmid-associated contig sequence possesses homologs of the bacteriocin/immunity factor complex first described in the M. catarrhalis plasmid, pLQ510 [24,26]; however, annotation records for this region also identify an incomplete VirB-family type four secretion system (T4SS), multiple transposases and a resolvase not reported in pLQ510, suggesting that this sequence may represent either an extra-chromosomally maintained conjugative plasmid or an integrative and conjugative element (ICE; recently reviewed in [27]). Phage-associated annotations varied between strains, but comprised only 0.2% to 2.5% of all identified ORFs per genome, while transposon-associated annotations accounted for only 0.15% to 0.44% of all ORFs per genome.…”

Section: Resultsmentioning

confidence: 99%

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Comparative analysis and supragenome modeling of twelve Moraxella catarrhalis clinical isolates

et al. 2011

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BackgroundM. catarrhalis is a gram-negative, gamma-proteobacterium and an opportunistic human pathogen associated with otitis media (OM) and exacerbations of chronic obstructive pulmonary disease (COPD). With direct and indirect costs for treating these conditions annually exceeding $33 billion in the United States alone, and nearly ubiquitous resistance to beta-lactam antibiotics among M. catarrhalis clinical isolates, a greater understanding of this pathogen's genome and its variability among isolates is needed.ResultsThe genomic sequences of ten geographically and phenotypically diverse clinical isolates of M. catarrhalis were determined and analyzed together with two publicly available genomes. These twelve genomes were subjected to detailed comparative and predictive analyses aimed at characterizing the supragenome and understanding the metabolic and pathogenic potential of this species. A total of 2383 gene clusters were identified, of which 1755 are core with the remaining 628 clusters unevenly distributed among the twelve isolates. These findings are consistent with the distributed genome hypothesis (DGH), which posits that the species genome possesses a far greater number of genes than any single isolate. Multiple and pair-wise whole genome alignments highlight limited chromosomal re-arrangement.ConclusionsM. catarrhalis gene content and chromosomal organization data, although supportive of the DGH, show modest overall genic diversity. These findings are in stark contrast with the reported heterogeneity of the species as a whole, as wells as to other bacterial pathogens mediating OM and COPD, providing important insight into M. catarrhalis pathogenesis that will aid in the development of novel therapeutic regimens.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Comparative analysis and supragenome modeling of twelve Moraxella catarrhalis clinical isolates

et al. 2011

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“…Normally, iterons are the site of binding of Rep initiation proteins and are located either upstream or downstream of the Rep protein gene. They usually have larger (17-to 22-bp) direct repeats, and there are usually several of them (8,18,28). Previously, we reported that clone I (pBM400) and clone II (pBM500) direct repeats are able to confer incompatibility for their own replicons but not for each other, which defined them as iterons (25).…”

Section: Resultsmentioning

confidence: 99%

Molecular Characterization of Plasmid pBM300 from Bacillus megaterium QM B1551

Kunnimalaiyaan

Vary

2005

Appl Environ Microbiol

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Strain QM B1551 of Bacillus megaterium contains seven compatible plasmids: two small rolling circle plasmids and five theta-replicating plasmids with cross-hybridizing replicons. To expand our understanding of these plasmids, the replicon region (6.7 kb) from pBM300 was cloned, sequenced, and functionally characterized. Sequence analysis showed that the replication protein (RepM300) was highly homologous to two other plasmid Rep proteins of the same strain but to no other known proteins. Furthermore, the location of the replication origin was within the RepM300 coding region, and the origin contained three 12-base direct repeats. Deletion analysis of the replicon confirmed the role of the Rep protein and showed that open reading frame 2 (ORF2) was required for stability. However, the protein encoded by ORF2 is entirely different from the replicon stability proteins encoded by the other two replicons. The entire plasmid was isolated from the plasmid array by integrating a spectinomycin resistance gene and transforming a plasmidless strain, PV361. Complete sequencing showed that pBM300 was 26,300 bp long, had a G؉C content of 35.2%, and contained 20 ORFs, two of which encoded proteins that had no similarity to other proteins in the database. The proteins encoded by the plasmid ORFs had similarity to proteins for mobilization and transfer, an integrase, a rifampin resistance protein, a cell wall hydrolase, glutathione synthase, and a biotin carboxylase. The similarities were to several gram-positive genera and a few gram-negative genera and archaea. oriT and ssoT-like regions were detected near two mob genes. These results suggest that pBM300 is a mobilizable hybrid plasmid that confers increased metabolic and germination ability on its host. Its replicon also helps define a new plasmid family.

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“…As reported previously [25], two of the ORFs in this plasmid were predicted to encode products with similarity to proteins involved in secretion of bacteriocins in other bacteria. Upon testing the E22 strain in a bacteriocin production assay using wild-type M. catarrhalis strain O35E as the indicator strain, the growth of the indicator strain was inhibited in the area immediately around the E22 strain (Figure 1C).…”

Section: Resultsmentioning

confidence: 68%

“…In a previous publication [25], ORF1 (now designated as M. c atarrhalis b acteriocin gene A or mcbA ) in pLQ510 (Figure 1E) was described as encoding a protein with homology to the colicin V secretion protein of E. coli [26] whereas ORF2 (now designated mcbB ) (Figure 1E) encoded a protein that was most similar to the colicin V secretion ATP-binding protein CvaB [26]. Analysis of the similarities between the amino acid sequences of the McbA and McbB proteins and those of proteins in sequence databases was next assessed using BLAST [blastp and PSI-BLAST [27]].…”

Section: Resultsmentioning

confidence: 99%

Identification of a bacteriocin and its cognate immunity factor expressed by Moraxella catarrhalis

et al. 2009

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BackgroundBacteriocins are antimicrobial proteins and peptides ribosomally synthesized by some bacteria which can effect both intraspecies and interspecies killing.ResultsMoraxella catarrhalis strain E22 containing plasmid pLQ510 was shown to inhibit the growth of M. catarrhalis strain O35E. Two genes (mcbA and mcbB) in pLQ510 encoded proteins predicted to be involved in the secretion of a bacteriocin. Immediately downstream from these two genes, a very short ORF (mcbC) encoded a protein which had some homology to double-glycine bacteriocins produced by other bacteria. A second very short ORF (mcbI) immediately downstream from mcbC encoded a protein which had no significant similarity to other proteins in the databases. Cloning and expression of the mcbI gene in M. catarrhalis O35E indicated that this gene encoded the cognate immunity factor. Reverse transcriptase-PCR was used to show that the mcbA, mcbB, mcbC, and mcbI ORFs were transcriptionally linked. This four-gene cluster was subsequently shown to be present in the chromosome of several M. catarrhalis strains including O12E. Inactivation of the mcbA, mcbB, or mcbC ORFs in M. catarrhalis O12E eliminated the ability of this strain to inhibit the growth of M. catarrhalis O35E. In co-culture experiments involving a M. catarrhalis strain containing the mcbABCI locus and one which lacked this locus, the former strain became the predominant member of the culture after overnight growth in broth.ConclusionThis is the first description of a bacteriocin and its cognate immunity factor produced by M. catarrhalis. The killing activity of the McbC protein raises the possibility that it might serve to lyse other M. catarrhalis strains that lack the mcbABCI locus, thereby making their DNA available for lateral gene transfer.

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Structural Analysis of Plasmid pLQ510 from Moraxella catarrhalis E22

Cited by 7 publications

References 26 publications

Comparative analysis and supragenome modeling of twelve Moraxella catarrhalis clinical isolates

Comparative analysis and supragenome modeling of twelve Moraxella catarrhalis clinical isolates

Molecular Characterization of Plasmid pBM300 from Bacillus megaterium QM B1551

Identification of a bacteriocin and its cognate immunity factor expressed by Moraxella catarrhalis

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