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A Muto

Publications and source records attributed to A Muto.

At least 145 records · Page 8Linked to original sources
PubMed1984

Nucleotide sequence of the rrnB 16S ribosomal RNA gene from Mycoplasma capricolum.

The nucleotide sequences of the rrnB 16S ribosomal RNA gene and its 5'-and 3'-flanking regions from Mycoplasma capricolum have been determined. The coding sequence is 1521 base pairs long, being 21 base pairs shorter than that of the Escherichia coli 16S rRNA gene. The 16S rRNA sequence of M. capricolum reveals 74% and 76% identify with that of E. coli and Anacystis nidulans, respectively. The secondary structure model constructed from the M. capricolum 16S rRNA gene sequence resembles that proposed for E. coli 16S rRNA. A large stem structure can be constructed between the 5'- and 3'-flanking sequences of the 16S rRNA gene. The flanking regions are extremely rich in AT.

Base Sequence↗
PubMed1984

Molecular cloning of ribosomal protein genes from Mycoplasma capricolum.

A Bg/II-fragment from the Mycoplasma capricolum DNA cloned into pBR322 has been found to contain a cluster of ribosomal protein genes. The recombinant plasmid, pMCB1088, includes a 9 kilobase-pair insert that codes for at least eight ribosomal proteins of M. capricolum. The protein genes are expressed in Escherichia coli cells.

Chromosome Deletion↗
PubMed1982

The protein composition of Mycoplasma capricolum.

The whole cell proteins and the ribosomal proteins of Mycoplasma capricolum ATCC 27343 have been analyzed by two-dimensional polyacrylamide gel electrophoresis. The M. capricolum cell is relatively rich in basic proteins. The number of total protein spots detected was approximately 355, which is less than one-third of that of Escherichia coli or Bacillus subtilis. In contrast, the number (30 and 20 protein species have been found to be present in the 50S and 30S ribosomal subunits, respectively) and the size of the ribosomal proteins in the M. capricolum do not seem to be significantly different from those of typical eubacteria.

Bacterial Proteins↗
PubMed1981

The number of ribosomal RNA genes in Mycoplasma capricolum.

We have examined the number of rRNA genes in Mycoplasma capricolum (KID) by hybridization of Bg/II-, EcoRI- and Xbal-digests of DNA to [3'-32P] 16S, 23S and 5S rRNAs according to the Southern procedure (1975). All the restriction gels gave two radioactive bands with three kinds of rRNA. Furthermore, band positions were indistinguishable from one another when 16S, 23S and 5S rRNAs were used as probes, indicating that each band contains sequences corresponding to the 3'-termini of 16S, 23S and 5S rRNAs. It is thus concluded that Mycoplasma capricolum chromosome carries at least two sets of genes for 16S, 23S and 5S rRNAs.

DNA Restriction Enzymes↗
PubMed1981

Control of ribosomal RNA synthesis in Escherichia coli. V. Stimulation of rrnC gene transcription in vitro by a protein factor.

Ribosomal RNA synthesis has been investigated in an in vitro system consisting of purified E. coli RNA polymerase and phi 80d3 DNA carrying rrnC operon. rRNA comprises about 25% of the total RNA synthesized in this system under optimal conditions and is stimulated by a crude protein fraction prepared from E. coli cell extracts. The stimulation activity has been fractionated by a Sephacryl S200 column and detected as a single peak of about 50,000 daltons molecular weight. The activity specifically increases the initiation frequency of transcription of the rRNA operon on the phage DNA. The addition of ppGpp partially inhibits the stimulation activity for rRNA synthesis.

Bacterial Proteins↗
PubMed1978

Control of ribosomal RNA synthesis in Escherichia coli. IV. Frequency of transcription of ribosomal RNA genes as a function of growth rate.

Nucleoids were isolated from Escherichia coli B/r cells in steady-stage growth at different rates. The number of RNA chains growing on each nucleoid was estimated from the amount and size of RNAs synthesized by endogenous RNA polymerase. This figure represents the number of RNA polymerase molecules that are functioning in transcription and thus serves to indicate the frequency of transcription in the cells. With an increase in the growth rate from 0.27 to 1.73 (h-1), (a) the number of total RNA chains per genome increases from about 252 to 838, (b) the number of ribosomal RNA (rRNA) chains per genome increases as a function of the second power of the growth rate from about 19 to 255, and (c) the number of non-rRNA chains per genome increases linearly from about 233 to 538.

DNA-Directed RNA Polymerases↗
PubMed1977

Control of ribosomal RNA synthesis in Escherichia coli. II. Ribosomal RNA synthesis in isolated nucleoids.

The effect of amino acid-starvation on the transcription in vitro of overall RNA and ribosomal RNA was investigated using nucleoids prepared from the exponentially growing and the amino acid-starved cells of rel+ and rel- strains of Escherichia coli. In this system, the synthesis of RNA is exclusively due to elongation of the chains which have been initiated in vivo. The amounts of overall and ribosomal RNA synthesized per unit of DNA in the nucleoids were analyzed for each preparation. The following observations have been made. (1) The total RNA synthesis per unit of DNA in the nucleoids from the amino acid-starved rel+ and rel- cells was not significantly different from each other. (2) The preferential ribosomal RNA synthesis occurred in the nucleoids from the growing cells; the ribosomal RNA synthesis was restricted in the nucleoids from the starved rel+ cells, while no restriction was observed in the nucleoids from the starved rel- cells. The results suggest that the ribosomal RNA synthesis is regulated at the initiation or less likely elongation level of the transcription. (3) A ribosomal RNA of a discrete size of about 30S was synthesized in the nucleoids. No mature ribosomal RNA species was produced in this system. The 30S RNA is probably a primary transcript of ribosomal RNA genes containing 23S, 16S and 5S mature ribosomal RNA sequences.

Cell-Free System↗
PubMed1977

Control of ribosomal RNA synthesis in Escherichia coli. III. Cytoplasmic factors for ribosomal RNA synthesis.

The ribosomal RNA synthesis in a cell-free system containing the nucleoids and the cytoplasmic fraction prepared from Escherichia coli cells has been investigated. The addition of the "4S" fraction from the cytoplasm to the isolated nucleoids induces RNA synthesis by a new chain initiation. In this system a preferential initiation or rRNA chains occurs. The experimental results suggest that the 4S fraction contains at least two activities, one for releasing RNA-polymerases from the nucleoids, and another for the frequent initiation of rRNA chains. No restriction of the rRNA synthesis has been observed in the nucleoids and the 4S fraction from the amino acid-starved rel+ cells. The rRNA synthesized in the above system is detected at about 23S and 16S rRNA regions.

Cell-Free System↗
PubMed1975

Correlation of 30S ribosomal proteins of Escherichia coli fractionated on carboxymethyl-cellulose column chromatography to the standard nomenclature.

The nomenclature proposed by Otaka et al. (1968) for the 30S ribosomal protein components of Escherichia coli as separated by carboxymethyl(CM)-cellulose column chromatography was adopted in several papers in which the genetic loci for many 30S ribosomal proteins on the E. coli chromosome were determined. In order to compare these data with those obtained in other laboratories, the 30S ribosomal proteins fractionated by CM-cellulose chromatography were correlated with thestandard nomenclature proposed by Wittmann et al. (1971).

Bacterial Proteins↗
PubMed1975

Effects of some antibiotics on the stringent control of RNA synthesis in Escherichia coli.

Effects of neomycin, spectinomycin, tetracycline and chloramphenicol on the stringent control RNA synthesis and on ppGpp synthesis in the rel+-cells of Escherichia coli having a temperature-sensitive valyl-tRNA synthetase were examined. Without antibiotics, ppGpp began to accumulate and both RNA and protein syntheses were inhibited by transferring the exponentially growing cells from 30 degrees C (permissive temp.) to 40 degrees C (non-permissive temp.). Tetracycline or chloramphenicol, when added after the temperature shift, caused a resumption of RNA synthesis and decay of the accumulated ppGpp, while neomycin or spectinomycin had little effect both on RNA synthesis and the level of ppGpp. When the cells were treated with these antibiotics at permissive temperature, the shift of the temperature to 40 degrees C caused neither inhibition of RNA synthesis nor an accumulation of ppGpp. When neomycin or spectinomycin was added at the beginning of the temperature shift, RNA synthesis continued with an accumulation of ppGpp. Tetracycline or chloramphenicol had no such effect under the same conditions; RNA synthesis continued without an accumulation of ppGpp.

Anti-Bacterial Agents↗
PubMed1975

Preferential ribosomal RNA synthesis in the lysate of Escherichia coli.

The RNA synthesis in non-viscous lysates containing the intact folded chromosome and cytoplasm fractions prepared from Escherichia coli has been examined in vitro. The RNA synthesis not only by chain extension but also by new chain initiation occurs in this system. While the RNA synthesis by chain extension takes place on the chromosome fraction alone (Pettijohn et al., 1970), an addition of the cytoplasm fraction is necessary for the synthesis by new chain initiations (de novo synthesis). Analyses of the in vitro synthesized RNA by hybridization-competition and by sucrose gradient centrifugation show that 16S and 23S ribosomal RNAs account for about 40% of the total RNA products. The cytoplasm fraction is required for the de novo synthesis of ribosomal RNA at high relative rate. Guanosine tetraphosphate (ppGpp) does not specifically inhibit ribosomal RNA synthesis in this system.

Cell-Free System↗
PubMed1975

Location and characteristics of ribosomal protein binding sites in the 16S RNA of Escherichia coli.

Specific binding sites for five proteins of the Escherichia coli 30S ribosomal subunit have been located within the 16S RNA. The sites are structurally diverse and range in size from 40 to 500 nucleotides; their functional integrity appears to depend upon both the secondary structure and conformation of the RNA molecule. Evidence is presented which indicates that additional proteins interact with the RNA at later stages of subunit assembly.

Bacterial Proteins↗