A Genetically Economical Family of Plasmid-Encoded Transcriptional Repressors Involved in Control of Plasmid Copy Number

Solar, Gloria del; Hernández‐Arriaga, Ana M.; Gomis‐Rüth, F. Xavier; Coll, Miquel; Espinosa, Manuel

doi:10.1128/jb.184.18.4943-4951.2002

Cited by 45 publications

(50 citation statements)

References 25 publications

(34 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In these bacterial plasmids, the copG gene is located upstream of a gene encoding a replication initiator protein and the two genes are expressed from a common promoter. The CopG protein binds to this promoter and represses the expression of both proteins, thus controlling the replication of the plasmid (del Solar et al, 2002). A similar organization exists in the Sulfolobus cryptic plasmid pRN1, where the copG gene precedes the gene for a RepA homologue (Keeling et al, 1998).…”

Section: Plasmid Replicationmentioning

confidence: 93%

See 1 more Smart Citation

Two novel conjugative plasmids from a single strain of Sulfolobus

et al. 2006

View full text Add to dashboard Cite

Two conjugative plasmids (CPs) were isolated and characterized from the same 'Sulfolobus islandicus' strain, SOG2/4. The plasmids were separated from each other and transferred into Sulfolobus solfataricus. One has a high copy number and is not stable (pSOG1) whereas the other has a low copy number and is stably maintained (pSOG2). Plasmid pSOG2 is the first Sulfolobus CP found to have these characteristics. The genomes of both pSOG plasmids have been sequenced and were compared to each other and the available Sulfolobus CPs. Interestingly, apart from a very well-conserved core, 70 % of the pSOG1 and pSOG2 genomes is largely different and composed of a mixture of genes that often resemble counterparts in previously described Sulfolobus CPs. However, about 20 % of the predicted genes do not have known homologues, not even in other CPs. Unlike pSOG1, pSOG2 does not contain a gene for the highly conserved PlrA protein nor for obvious homologues of partitioning proteins. Unlike pNOB8 and pKEF9, both pSOG plasmids lack the so-called clustered regularly interspaced short palindrome repeats (CRISPRs). The sites of recombination between the two genomes can be explained by the presence of recombination motifs previously identified in other Sulfolobus CPs. Like other Sulfolobus CPs, the pSOG plasmids possess a gene encoding an integrase of the tyrosine recombinase family. This integrase probably mediates plasmid site-specific integration into the host chromosome at the highly conserved tRNA Glu loci.

show abstract

Section: Plasmid Replicationmentioning

confidence: 93%

“…Sequence similarity indicates that ORF62 belongs to the CopG family, a copy number control protein used by numerous bacterial plasmids (del Solar et al, 2002). In these bacterial plasmids, the copG gene is located upstream of a gene encoding a replication initiator protein and the two genes are expressed from a common promoter.…”

Section: Plasmid Replicationmentioning

confidence: 99%

Two novel conjugative plasmids from a single strain of Sulfolobus

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Thus, the dimer would have a ribbon-helix-helix (RHH) motif, by which it would bind to its target DNA, similar to the Arc-CopG-Omega family of transcriptional repressors (37,62,111,121); in fact, the 28 N-terminal amino acids of the pneumococcal RelB protein share 64% similarity with the 45-residue CopG transcriptional repressor encoded by streptococcal plasmid pMV158 (37,105). The RHH DNA-binding motif also seems to be present in the N-terminal regions of the RelB and YefM proteins from E. coli (79,93,119) and in the pneumococcal RelB2 protein (105) but not in the archaeal RelB proteins (53,138) or in the pneumococcal YefM protein (our unpublished observations).…”

Section: Structural Informationmentioning

confidence: 99%

Toxin-Antitoxin Genes of the Gram-Positive Pathogen Streptococcus pneumoniae: So Few and Yet So Many

Chan

Moreno-Córdoba

Yeo

et al. 2012

Microbiol Mol Biol Rev

Self Cite

127

View full text Add to dashboard Cite

SUMMARYPneumococcal infections cause up to 2 million deaths annually and raise a large economic burden and thus constitute an important threat to mankind. Because of the increase in the antibiotic resistance ofStreptococcus pneumoniaeclinical isolates, there is an urgent need to find new antimicrobial approaches to triumph over pneumococcal infections. Toxin-antitoxin (TA) systems (TAS), which are present in most living bacteria but not in eukaryotes, have been proposed as an effective strategy to combat bacterial infections. Type II TAS comprise a stable toxin and a labile antitoxin that form an innocuous TA complex under normal conditions. Under stress conditions, TA synthesis will be triggered, resulting in the degradation of the labile antitoxin and the release of the toxin protein, which would poison the host cells. The three functional chromosomal TAS fromS. pneumoniaethat have been studied as well as their molecular characteristics are discussed in detail in this review. Furthermore, a meticulous bioinformatics search has been performed for 48 pneumococcal genomes that are found in public databases, and more putative TAS, homologous to well-characterized ones, have been revealed. Strikingly, several unusual putative TAS, in terms of components and genetic organizations previously not envisaged, have been discovered and are further discussed. Previously, we reported a novel finding in which a unique pneumococcal DNA signature, the BOX element, affected the regulation of the pneumococcalyefM-yoeBTAS. This BOX element has also been found in some of the other pneumococcal TAS. In this review, we also discuss possible relationships between some of the pneumococcal TAS with pathogenicity, competence, biofilm formation, persistence, and an interesting phenomenon called bistability.

show abstract

“…The TraY protein from the E. coli episome F is also an RHH tandem repeat (50), but its structure is unknown. The MetJ (24), Arc (21), ⍀ (18), and CopG (11,(27)(28)(29) RHH proteins all bind to their DNA recognition sites as dimers of dimers.…”

Section: Discussionmentioning

confidence: 99%

“…Among them, the methionine repressor MetJ (24), the regulator of plasmid copy number CopG (11,(27)(28)(29), and the bacte-riophage P22 Mnt and Arc repressors (21,30) could be considered the prototypical RHH proteins. The RHH motif consists of an N-terminal ␤-strand and two ␣-helices connected by a short turn.…”

mentioning

confidence: 99%

Structure and Function of AvtR, a Novel Transcriptional Regulator from a Hyperthermophilic Archaeal Lipothrixvirus

Peixeiro

Keller

Collinet

et al. 2013

J Virol

View full text Add to dashboard Cite

The structural and functional analysis of the protein AvtR encoded by Acidianus filamentous virus 6 (AFV6), which infects the archaeal genus Acidianus, revealed its unusual structure and involvement in transcriptional regulation of several viral genes. The crystal structure of AvtR (100 amino acids) at 2.6-Å resolution shows that it is constituted of a repeated ribbon-helix-helix (RHH) motif, which is found in a large family of bacterial transcriptional regulators. The known RHH proteins form dimers that interact with DNA using their ribbon to create a central ␤-sheet. The repeated RHH motifs of AvtR superpose well on such dimers, but its central sheet contains an extra strand, suggesting either conformational changes or a different mode of DNA binding. Systematic evolution of ligands by exponential enrichment (SELEX) experiments combined with systematic mutational and computational analysis of the predicted site revealed 8 potential AvtR targets in the AFV6 genome. Two of these targets were studied in detail, and the complex role of AvtR in the transcriptional regulation of viral genes was established. Repressing transcription from its own gene, gp29, AvtR can also act as an activator of another gene, gp30. Its binding sites are distant from both genes' TATA boxes, and the mechanism of AvtR-dependent regulation appears to include protein oligomerization starting from the protein's initial binding sites. Many RHH transcriptional regulators of archaeal viruses could share this regulatory mechanism.

show abstract

A Genetically Economical Family of Plasmid-Encoded Transcriptional Repressors Involved in Control of Plasmid Copy Number

Cited by 45 publications

References 25 publications

Two novel conjugative plasmids from a single strain of Sulfolobus

Two novel conjugative plasmids from a single strain of Sulfolobus

Toxin-Antitoxin Genes of the Gram-Positive Pathogen Streptococcus pneumoniae: So Few and Yet So Many

Structure and Function of AvtR, a Novel Transcriptional Regulator from a Hyperthermophilic Archaeal Lipothrixvirus

Contact Info

Product

Resources

About