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W Messer

Publications and source records attributed to W Messer.

At least 91 records · Page 5Linked to original sources
PubMed1983

The replication origin region of Escherichia coli: nucleotide sequence and functional units.

The minichromosome pCM959 contains the DNA segment from bp -677 (left) to bp + 3335 (right) of the Escherichia coli replication origin, oriC. The nucleotide sequence of this plasmid was determined. The coding regions for proteins were identified, and the possible function of those proteins is discussed. Within oriC two extended systems of dyad symmetry were found, and their possible significance is considered.

Bacterial Proteins↗
PubMed1982

Purification of the E. coli dnaA gene product.

The product of the dnaA gene of Escherichia coli was isolated in a highly enriched form. The purification product binds specifically to DNA containing the E. coli chromosomal origin of replication, oriC.

Bacterial Proteins↗
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

[Transdermal salicylate absorption following epidermal application of an analgesic / antiphlogistic ointment and gel formulation (author's transl)].

Following epidermal application of 5 g Dolo-Arthrosenex ointment for gel, respectively, containing 625 mg ethyleneglycol salicylate (corresponding to 473.9 mg salicylic acid) upon a skin area of 100 cm2 of 12 normal volunteers transdermal absorption of salicylate was measured over a period of 48 h after application by means of renal salicylate excretion. A high-pressure liquid chromatography method was employed for the quantitative estimation of urinary levels of salicylic acid and salicyluric acid. Afer application of the ointment in the mean 26.7% of the applied salicylate dose is resorbed within 24 h and excreted within 48 h, respectively. From the gel in the mean 48.0% of the applied salicylate dose is absorbed within 24 h and excreted within 48 h, respectively.

Adult↗
PubMed1980

Functional analysis of minichromosome replication: bidirectional and unidirectional replication from the Escherichia coli replication origin, oriC.

Replicating molecules of minichromosomes pCM959 and pOC24 were analyzed by electron microscopy. Replication of pCM959 proceeded bidirectionally from the replication origin, oriC, in about 60% of the molecules; the rest of the molecules replicated unidirectionally in either direction. pOC24, in which deoxyribonucleic acid to the right (clockwise) of the oriC segment is deleted, seemed to replicate predominantly unidirectionally counterclockwise from oriC.

Base Sequence↗
PubMed1979

Control of the initiation of DNA replication in Escherichia coli. I. Negative control of initiation.

A transient stimulation of the initiation of DNA replication during inhibition of protein synthesis has been demonstrated in dnaA5 and dnaA46 mutants. This suggests the existence of a negatively acting control protein (not the dnaA product) which decays rapidly or is removed during a block in protein synthesis. The stimulation of initiation is dependent on a previous accumulation of initiation specific proteins, which suggests that in addition to the negative control other control mechanisms are effective.

Alleles↗
PubMed1979

Control of the initiation of DNA replication in Escherichia coli. II. Function of the dnaA product.

General growth parameters and the kinetics of DNA replication have been determined in merogenotes carrying different combinations of the dnaA+ and the dnaA5 allele. The strain which is homozygous diploid for dnaA5 is different from all other combinations in cell volume, DNA per mass ratio, number of replication points per chromosome, and polymerization rate of DNA. From this we deduce that the dnaA product is a positively acting regulatory protein in initiation. In an appendix we show that in combinations between the dnaA5 and dnaA204 alleles the phenotype of dnaA5 is dominant.

Alleles↗
PubMed1979

Nucleotide sequence of the origin of replication of the Escherichia coli K-12 chromosome.

The origin of replication, oriC, of the Escherichia coli chromosome was mapped within a DNA segment of 422 base pairs. The nucleotide sequence of this segment was determined. The source of DNA for the sequence analysis was a minichromosome constructed in vivo, consisting exclusively of chromosomal DNA and a minichromosome constructed by cloning in vitro. The nucleotide sequence of the replication origin is characterized by a high degree of repetitiveness due to both inverted and direct repeats. Sequence homologies were found between portions of the replication origins of E. coli and phages lambda and G4. This suggests similarities in some steps in the initiation of replication of the different replicons.

Base Sequence↗
PubMed1978

Mini-chromosomes: plasmids which carry the E. coli replication origin.

We have isolated plasmids by linking the 5.9 MD EcoRI fragment of E. coli that carries the origin of replication to an EcoRI fragment that carries an amplicillin resistance determinant, but lacks an origin of replication. 3 plasmids of this type, pOC1, pOC2, and pOC3, are described in detail in this report. Although the plasmids have some adverse effect on the growth properties of the host strain, their existence shows that two functioning chromosomal origins can coexist in one cell. Deletions generated from this type of plasmids allow an allocation of the origin of replication of E. coli within a DNA segment less than 0.4 MD in size.

Ampicillin↗
PubMed1977

Trans-dominance of dnaA mutants in Escherichia coli.

Temperature sensitivity of growth and DNA synthesis was tested in merogenotes heterozygous for the dnaA allele. All combinations tested (F dnaA+/dnaA5, F dnaA+/dnaA46, F dnaA+/dnaA204, F dnaA5/dnaA+, F dnaA204/dnaA+) were temperature sensitive. The mutant dnaA allele is thus trans-dominant to the wild type allele.

Alleles↗
PubMed1977

Oscillations in the synthesis of cell wall components in synchronized cultures of Escherichia coli.

The rate of cell wall synthesis with respect to both proteins and lipids was determined in synchronized cultures of Escherichia coli B/r. Whereas the rate of total protein synthesis showed an exponential increase with cell age, the rate of incorporation of proteins and lipids into cell wall had a maximum at a cell age of 30 to 35 min, 15 min before cell division. This oscillation was observed in both the cytoplasmic membrane and in the outer membrane of the cell envelope.

Acetates↗
PubMed1977

Activity of murein hydrolases in synchronized cultures of Escherichia coli.

Murein hydrolase activities were analyzed in synchronized cultures of Escherichia coli B/r. Cell wall-bound murein hydrolase activities, including the penicillin-sensitive endopeptidase, increased discontinuously during the cell cycle and showed maximum activity at a cell age of 30 to 35 min (generation time, 43 min). Maximum activity was observed at the same time that the rate of cell wall synthesis reached its maximum. These oscillations depended on the termination of replication: no increase in hydrolase activity was found if deoxyribonucleic acid synthesis was inhibited at an early time in the life cycle. In contrast, the activity of another murein hydrolase that was not tightly bound to the membrane (transglycosylase) increased exponentially with time, even when deoxyribonucleic acid synthesis was inhibited.

Bacterial Proteins↗
PubMed1976

Histochemical staining in lymphocyte suspensions complexed with beta-galactosidase as an antigen. Unspecific staining of spleen cells by indigo.

Spleen cells from mice immunized with E. coli beta-galactosidase were incubated with the enzyme and with 5-bromo-4-chloroindolyl-beta-galactosidase as a histochemical substrate. Some cells are stainable in this reaction, however, not all of them carry specific receptors for beta-galactosidases. Some spleen cells can take up dye and thereby become unspecifically stained. This system is therefore not suitable for the detection of antigen binding to cells.

Animals↗