PubMed Health⌕ Search

Biomedical subjects

T A Trautner

Publications and source records attributed to T A Trautner.

At least 55 records · Page 3Linked to original sources
PubMed1987

Recombinant derivatives of Bacillus subtilis phage Z containing the DNA methyltransferase genes of related methylation-proficient phages.

The DNA methyltransferase (Mtase) genes of temperate Bacillus subtilis phages SPR, phi 3T, SP beta and rho 11 can be transferred by transfection and recombination to the genome of the related non-modifying phage Z. Integration of the Mtase genes occurs in phage Z DNA at a unique location which is homologous with the flanking regions of the Mtase genes of the related phages. In lysogenic cells carrying recombinant phages, expression of the Mtase genes is repressed, irrespective of whether the Mtase genes were derived from phage donors which were homo- or heteroimmune to phage Z.

Bacillus subtilis↗
PubMed1986

Requirements for the formation of plasmid-transducing particles of Bacillus subtilis bacteriophage SPP1.

We had previously proposed that the production of concatemeric plasmid DNA in plasmid-transducing SPP1 particles is a consequence of phage-directed rolling-circle-type replication of plasmid DNA. The production of such DNA was greatly enhanced when DNA/DNA homology was provided between phage and plasmid DNAs (facilitation of transduction). Here we present evidence that synthesis of concatemeric plasmid DNA can proceed after phage infection under conditions non-permissive for plasmid replication. We also propose that the naturally occurring homology between plasmid and phage is sufficient to account for the frequency of transduction observed in the absence of facilitating homology. Homology of greater than 47 bp gives the maximal facilitation of plasmid transduction. Recombination is not an essential part in the synthesis of concatemeric plasmid DNA.

Bacillus subtilis↗
PubMed1986

DNA methyltransferase genes of Bacillus subtilis phages: comparison of their nucleotide sequences.

The phi 3T DNA methyltransferase (Mtase) and most of the SP beta Mtase genes have been sequenced. With the exception of their promoters, no difference was found between the phi 3T and SP beta Mtase genes which code for an enzyme with a Mr of 50 507, consisting of 443 amino acids (aa). Comparison of the deduced aa sequence of the phi 3T/SP beta type Mtase (target specificity: GGCC and GCNGC) with that of the previously established sequence of the SPR Mtase (Buhk et al., 1984) which has the target specificity GGCC and CCGG, reveals strong similarities between these two types of enzymes. There is, however, one striking difference: both the phi 3T/SP beta and the SPR enzymes contain at different positions inserts of 33 aa, which have no homology to each other. We suggest that the methylation specificity unique to each of the two types of Mtases (GCNGC in phi 3T/SP beta; CCGG in SPR) depends on these inserts, while the GGCC-specific modification potential common to all Mtases is determined by structures conserved in both types of enzymes. A DNA fragment of non-modifying phage Z, which shows homology to both flanks of the SPR Mtase gene, was also sequenced. This segment can be described as a derivative of SPR DNA, in which the Mtase gene and sequences at its 5' end have been deleted, with the deletion extending between two direct repeats of 25 bp.

Amino Acid Sequence↗
PubMed1986

Genomic organization of the related Bacillus subtilis bacteriophages SPP1, 41c, rho 15, and SF6.

The genomes of the related virulent Bacillus subtilis bacteriophages SPP1, 41c, rho 15, and SF6 are partially circularly permuted and terminally redundant. Heteroduplex molecules were produced with various combinations of these DNAs. Their electron-microscopic analyses showed a consistent pattern of homologous and heterologous regions of DNA. Restriction maps of the phage DNAs were established. A comparison of these maps showed a pattern of conserved and variable DNAs compatible with the electron-microscopic analyses. In all phage genomes, regions specifying early and late functions were conserved. In each phage genome, such regions were separated by short segments of heterologous DNA characteristic for each phage.

Bacillus subtilis↗
PubMed1985

A gene controlling segregation of the Bacillus subtilis plasmid pC194.

Plasmid pC194-1, a mutant of pC194, and chimeric derivatives of pC194-1 are segregationally unstable in B. subtilis. Such instability could be enhanced by exposure of pC194-1-carrying cells to methyl methanesulfonate. pC194-1 is distinct from pC194 in the addition of two A:T base pairs within the previously defined D region of pC194. Complementation experiments between pC194-1 and other plasmids suggest that the mutation of pC194-1 interferes with the production of a diffusible gene product required for plasmid maintenance.

Bacillus subtilis↗
PubMed1985

Generation of deletions through a cis-acting mutation in plasmid pC194.

When plasmid pC194-1 is ligated to pBR322 to generate plasmid pHV15-1, deletions occur with high frequency within the joined pBR322 DNA. Generation of deletions is recE4 independent, and occurs in B. subtilis with a 1,000-fold higher frequency than in Escherichia coli. In the hybrid plasmid pVH15-1, deletion end-points are not at random, but at defined locations within pBR322. We propose that the base alteration, characterizing pC194-1, has stabilized within the plasmid a stem/loop structure, which acts as a deletion generator.

Bacillus subtilis↗
PubMed1985

Cold sensitivity in the transfer of a plasmid with a deletion hot spot into recombination deficient B. subtilis cells.

Various recombination-deficient mutants of B. subtilis, which are readily transformable by plasmid DNA at 42 degrees C cannot be transformed at 30 degrees C with chimeric plasmid derivatives that contain the deletion hot spot defined previously (Alonso and Trautner 1985a, b). Such interference was also observed in protoplast transformation and SPP1 transduction.

Bacillus subtilis↗
PubMed1985

Inversion and deletion mutants in Bacillus subtilis bacteriophage SPP1 as a consequence of cloning.

Properties of an inversion and a deletion mutant of B. subtilis phage SPP1 which arose during cloning are described. The results are related to the biology of this bacteriophage. In preceding communications from our laboratories (Heilmann and Reeve 1982, Behrens et al. 1983) we reported the properties of genetically engineered SPP1 bacteriophages, which could be used as cloning vehicles in B. subtilis. These phages contain a unique restriction site within a dispensable region of their genomes. In the course of cloning experiments using these phage vectors, we have occasionally observed the appearance of not only the original vector and desired hybrid phages, but also of SPP1 phages which had undergone extensive genomic rearrangements. Properties of two such phages, SPP1 inv1, which was found to contain a large inversion and of SPP1 delV, a deletion mutant, which defines an additional dispensable region of the SPP1 genome, are described in this communication.

Bacillus subtilis↗
PubMed1985

DNA methyltransferase genes of Bacillus subtilis phages: structural relatedness and gene expression.

The DNA methyltransferase (Mtase) genes of temperate Bacillus subtilis phages phi 3T, rho 11 and SP beta were cloned and expressed in Escherichia coli. Each gene specifies a 47-kDa1 protein, which modifies BsuR (GGCC) and Fnu4HI (GCNGC) target sequences. Transcription is controlled by phage promoters located on the cloned fragments. The direction of transcription and the approximate position of the Mtase genes were determined. DNA/DNA hybridization experiments revealed close structural relatedness of the phi 3T, rho 11 and SP beta genes. A significant degree of homology was also found among these genes and the Mtase gene of related phage SPR, which codes for an enzyme with different modification specificity. These results suggest a common ancestor of the different phage Mtase genes. Phage Z, the only BsuR-sensitive member of this phage group, lacks a modification gene, but contains regions homologous to sequences flanking the SPR, phi 3T, rho 11 and SP beta Mtase genes.

Bacillus subtilis↗
PubMed1985

The genome of Bacillus subtilis phage SPP1: structure of an early promoter.

The strongest of five 'early' promoters of Bacillus subtilis phage SPP1 was localized in a DNA restriction fragment by analysis of RNA polymerase binding and R-loop formation. The nucleotide sequence of the promoter region was established. The signal structures identified were similar to those recognized by the sigma 55 RNA polymerase of B. subtilis. The promoter precedes an open reading frame with 51 codons. A protein with the Mr predicted from the nucleotide sequence was identified in minicells.

Autoradiography↗
PubMed1985

Plasmid transduction by Bacillus subtilis bacteriophage SPP1: effects of DNA homology between plasmid and bacteriophage.

Any SPP1 DNA restriction fragment cloned into Bacillus subtilis plasmid pC194 or pUB110 increased the transduction frequency of the plasmid by SPP1 100- to 1,000-fold over the transduction level of the plasmid alone. This increment was observed irrespective of whether a fragment contained the SPP1 packaging origin (pac). Furthermore, an SPP1 derivative into whose genome pC194 DNA had been integrated transduced pC194 DNA with a greatly enhanced frequency. Transduction enhancement mediated by DNA-DNA homology between plasmid and SPP1 was independent of the extent of homology (size range analyzed, 0.5 to 3.9 kilobases) and the recombination proficiency of donor or recipient.

Bacillus subtilis↗
PubMed1984

Plasmid transformation in Bacillus subtilis: factors affecting the synapsis of donor and recipient DNA.

Hybrid plasmids were constructed in which the transcription of regions of inserted DNA was defined. Cells containing these plasmids were transformed with monomeric forms of a different hybrid plasmid, which contained, however, the same inserted DNA as the resident plasmid. The transformation frequencies observed indicated that transcription of homologous DNA in resident plasmids and also tertiary DNA structure interfered with transformation.

Bacillus subtilis↗
PubMed1983

Restriction and modification in Bacillus subtilis: expression of the cloned methyltransferase gene from B. subtilis phage SPR in E. coli and B. subtilis.

Expression of the SPR methyltransferase gene from B. subtilis phage SPR cloned into lambda and SPP1 was studied by analyzing the sensitivity of the hybrid phage DNAs to restriction by the enzymes HaeIII, MspI, and HpaII. The following results were obtained: (1) The genes were expressed both in the homologous (B. subtilis) and heterologous (E. coli) host. (2) The specificity of the expression of the cloned gene was identical to that of the gene in SPR. (3) Expression depended on the orientation of the cloned segment within the vector DNAs suggesting that vector promoters were involved in transcription. The coding strand of the cloned DNA was identified through hybridization with SPR mRNA.

Bacillus subtilis↗
PubMed1983

Plasmid transformation in Bacillus subtilis. Effects of the insertion of Bacillus subtilis rRNA genes into plasmids.

Two HindIII generated DNA fragments of 3.0 and 2.3 Kb derived from rRNA genes of B. subtilis were cloned in E. coli with pBR322. The 3.0 Kb fragment could be subcloned in B. subtilis using pC194. However, only the multimeric, but not the monomeric derivatives of this hybrid plasmid were active in transformation of B. subtilis cells. The 2.3 Kb fragment could neither be subcloned in pC194 nor in pPL603, using both cell and protoplast transformation. We attribute the nonclonability of the 2.3 Kb fragment in B. subtilis to the presence of strong promoter activity in this fragment. Direct proof for the presence of a strong promoter, which is apparently responsible for the transcription of the rRNA gene, was obtained in experiments with B. subtilis and E. coli promoter search plasmids.

Bacillus subtilis↗
PubMed1983

Restriction and modification in Bacillus subtilis: DNA methylation potential of the related bacteriophages Z, SPR, SP beta, phi 3T, and rho 11.

The DNA methylation capacity and some other properties of the related temperate Bacillus subtilis phages Z, SPR, SP beta, phi 3T, and rho 11 are compared. With phage mutants affected in their methylation potential, we show that phage-coded methyltransferase genes are interchangeable among the phages studied. DNA/DNA hybridization experiments indicate that phage methyltransferase genes are structurally related, whereas no such relationship is observed to a bacterial gene, specifying a methyltransferase with the same specificity.

Bacillus subtilis↗
PubMed1982

Genome of Bacillus subtilis Bacteriophage SPP1: Structure and Nucleotide Sequence of pac, the Origin of DNA Packaging.

The DNA of Bacillus subtilis bacteriophage SPP1 is terminally redundant and partially circularly permuted. To explain these parameters, we followed the Streisinger-Botstein models of phage maturation and assumed that packaging of SPP1 DNA begins at a unique genomic site ("pac") and proceeds sequentially from there. We describe the sequence of about 1,000 nucleotides surrounding pac. This together with size determinations of small, pac-terminated restriction fragments has revealed heterogeneity of the natural pac ends of SPP1 DNA. Such ends fell in each DNA strand into a region of five to seven nucleotides. However, within this range more than 50% of all molecules terminated with defined cytosines on both strands, generating a 3' protruding terminus. The nucleotide sequence of the DNA segment surrounding pac did not reveal any features which would distinguish this region.

Journal Article↗
PubMed1982

SPP1-mediated plasmid transduction.

The virulent Bacillus subtilis phage SPP1 transduces plasmid DNA. Plasmid-transducing phages contain only plasmid DNA. Such DNA represents a concatemer of monomeric plasmid molecules with the molecular weight of mature SPP1 DNA. Biological parameters of plasmid transduction are described.

Bacillus subtilis↗