The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The complete nucleotide sequence of a new cryptic plasmid pAR67 isolated from a rumen bacteriumRuminococcus albusAR67 has been determined. The plasmid pAR67 was 3419 bp in size with a 45% GC content. Two open reading frames, ORF1 and ORF2, encoding potential polypeptides of 285 and 165 amino acids, with limited sequence similarity to replication and mobilization proteins, respectively, were identified...
The unwinding of the origin of replication (oriC) is a critical step in initiation of DNA replication inEscherichia coli.Previous observations indicate that efficient unwinding of supercoiled plasmid templates containingoriCsequences requires the DnaA initiation protein and one or more accessory factors. The precise contribution of each protein to this process is unknown. Here, we demonstrate that...
The nucleotide sequence of the 3.5-kb right junction fragment of the streptococcal conjugative transposon Tn5252was obtained. The DNA fragment was found to carry four putative genes one of which displayed a high degree of similarity to prokaryotic 5C-cytosine methyltransferases carrying multiple sequence specificities. No cognate endonuclease gene was detected in the sequenced DNA. Purified methylase...
The term “plasmid” was introduced 45 years ago (J. Lederberg, 1952,Physiol. Rev.32,403–430) as a generic term for any extrachromosomal genetic particle. It was intended to clarify the classification of agents that had been thought of disjunctively as parasites, symbionts, organelles, or genes. For a decade or more it was confused with “episome,” although that was carefully crafted (F. Jacob and E...
Differential replication of various ColE1-type plasmids in stringent (relA + ) and relaxed (relA − ) strains ofEscherichia colistarved for particular amino acids was reported previously. A role for the plasmid-encoded Rom protein in the stringent control of ColE1 replication has also been demonstrated. Here we have studied the efficiency of replication of five ColE1-type plasmids inE...
The incompatibility properties of two tumor-inducing (Ti) and seven tartrate (Tr) plasmids, derived from variousAgrobacterium vitisstrains, were characterized usingincRh1,incRh2,incRh3, andincRh4 clones which were established for the identification and classification ofAgrobacteriumplasmids. The testedA. vitisplasmids could be allocated into four groups on the basis of their incompatibility withincRh1,incRh2,...
Escherichia coliDNA gyrase B subunit (GyrB) is composed of a 43-kDa N-terminal domain containing an ATP-binding site and a 47-kDa C-terminal domain involved in the interaction with the gyrase A subunit (GyrA). Site-directed mutagenesis was used to substitute, in both the entire GyrB subunit and its 43-kDa N-terminal fragment, the amino acid Y5 by either a serine (Y5S) or a phenylalanine residue (Y5F)...
An insertion element (IS)4insertion selected as suppressor of therpoN73::Tn5alelle was located inside the control region of theglnAgene inEscherichia coli.In therpoN73::Tn5background the IS4insertion promotesglnAtranscription at a low constitutive level sufficient to sustain glutamine-independent growth. The IS4insertion mutation in eitherrpoN73::Tn5or wild-type backgrounds promotesglnAtranscription...
TheKlebsiella pneumoniaeplasmid pJHCMW1 harbors a copy of Tn1331,a multiresistance transposon that includes theaac(6′)-Ibgene which encodes a 6′-N-aminoglycoside acetyltransferase. This gene was mutagenized using the mutatorEscherichia coliXL1-Red. Two plasmids with a single nucleotide mutation inaac(6′)-Ibwere selected for further analysis: pDP1 and pDP6. Plasmid pDP1 codes for a mutant enzyme, AAC(6′)-Ib...
The pBG1 replicon from the cryptic plasmid ofDesulfovibrio desulfuricansG100A was inserted into pTZ18U derivatives to generate a new family of shuttle vectors. These plasmids are stable both inEscherichia coliand inDesulfovibrio,they present a large number of unique restriction sites, and colonies of recombinant clones can be identified by blue/white screening inE. coli.The pBMC, pBMK, and pBMS series...
A chromosomally integrated copy of the IncP plasmid RP4 was shown to mediate the conjugative transfer of shuttle plasmids containing anoriTsite fromEscherichia colito the anaerobic pathogenClostridium perfringens.Two versatile shuttle plasmids, pJIR1456 and pJIR1457, which will be invaluable for the introduction of cloned genes intoC. perfringens,were constructed.
A 102-kb plasmid, pIJB1, was isolated fromBurkholderia cepaciastrain 2a, which is able to use 2,4-dichlorophenoxyacetate (2,4-D) as a sole carbon source, and a physical map of the plasmid has been established. It was observed that spontaneous loss of a 37-kb fragment of the plasmid after growth in nonselective medium occurred, generating a plasmid of diminished size, pIJB2. The deletion event is concomitant...
We investigated the establishment of integrating transformation vectors in the genome ofDictyostelium discoideumto gain insight into the formation of the plasmid insertions and to investigate the conditions that determine the number of plasmid copies present in such insertions. Transformation vectors conferring resistance to neomycin and/or blasticidin were introduced into the cell as a calcium phosphate...
A restriction enzyme map was constructed of a 3.3-kb plasmid derived from enterohemorrhagicEscherichia coliO157:H7 strain 4821 using the enzymesSmaI,HpaI,FokI,HaeIII,StyI,RsaI,BglII,ClaI, andEcoRV. The molecular size of p4821 was 3307 bp, determined by nucleotide sequencing. Homology searches in the EMBL database library revealed that the nucleotide sequence of p4821 is similar (>98%) to the core...
Isolation and characterization of four different insertion sequence (IS) elements fromPseudomonas glumaeMAFF 302744 through transposition into the entrapment vector pSHI1063 are described. One of the elements, IS1416,was further characterized. IS1416is 1322 bp long and carries 29-bp terminal inverted repeats flanked by a 3-bp direct duplication. IS1416contains three open reading frames (ORFs), which...
Histamine production in bacteria-contaminated fish is the result of the presence of bacterial histidine decarboxylase activity, which converts histidine present in muscle proteins to histamine. The fish pathogenVibrio anguillarumharbors a plasmid-encoded histidine decarboxylase gene (angH) that is essential for biosynthesis of the siderophore anguibactin. However, the role ofangHin histamine biosynthesis...
The random distribution of ColE1 plasmids between the daughter cells at cell division introduces large copy number variations. Statistic variation associated with limited copy number in single cells also causes fluctuations to emerge spontaneously during the cell cycle. Efficient replication control out of steady state is therefore important to tame such stochastic effects of small numbers. In the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.