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At least 19 recordsLinked to original sources
PubMed2005

A phylogeny of bacterial RNA nucleotidyltransferases: Bacillus halodurans contains two tRNA nucleotidyltransferases.

We have analyzed the distribution of RNA nucleotidyltransferases from the family that includes poly(A) polymerases (PAP) and tRNA nucleotidyltransferases (TNT) in 43 bacterial species. Genes of several bacterial species encode only one member of the nucleotidyltransferase superfamily (NTSF), and if that protein functions as a TNT, those organisms may not contain a poly(A) polymerase I like that of Escherichia coli. The genomes of several of the species examined encode more than one member of the nucleotidyltransferase superfamily. The function of some of those proteins is known, but in most cases no biochemical activity has been assigned to the NTSF. The NTSF protein sequences were used to construct an unrooted phylogenetic tree. To learn more about the function of the NTSFs in species whose genomes encode more than one, we have examined Bacillus halodurans. We have demonstrated that B. halodurans adds poly(A) tails to the 3' ends of RNAs in vivo. We have shown that the genes for both of the NTSFs encoded by the B. halodurans genome are transcribed in vivo. We have cloned, overexpressed, and purified the two NTSFs and have shown that neither functions as poly(A) polymerase in vitro. Rather, the two proteins function as tRNA nucleotidyltransferases, and our data suggest that, like some of the deep branching bacterial species previously studied by others, B. halodurans possesses separate CC- and A-adding tRNA nucleotidyltransferases. These observations raise the interesting question of the identity of the enzyme responsible for RNA polyadenylation in Bacillus.

Amino Acid Sequence↗
PubMed1973

Turnip Yellow Mosaic Virus RNA as a Substrate of the Transfer RNA Nucleotidyltransferase II. Incorporation of Cytidine 5'-Monophosphate and Determination of a Short Nucleotide Sequence at the 3' End of the RNA.

Turnip yellow mosaic virus (TYMV) RNA treated with snake venom phosphodiesterase accepts cytidine 5'-monophosphate and adenosine 5'-monophosphate (AMP) when it is incubated in the presence of cytidine 5'-triphosphate (CTP), adenosine 5'-triphosphate, and Escherichia coli transfer RNA nucleotidyltransferase; untreated TYMV RNA accepts only AMP. When alpha (32)PCTP was used for terminal labeling, the nearest neighbor analyses and the anallyses after action of various nucleases showed that the sequence of five nucleotides at the 3' end of TYMV RNA is: pGpCpApCpC. A nuclease present in commerical preparations of snake venom phosphodiesterase leads to the fragmentation of TYMV RNA, the 3' end of which is found in a fragment having a sedimentation constant close to 5s.

Journal Article↗
PubMed1975

A novel function of Escherichia coli transfer RNA nucleotidyltransferase. Biosynthesis of the C-C-A sequence in a phage T4 transfer RNA precursor.

The biosynthesis of the phage T4-coded proline and serine transfer RNA species proceeds through a precursor RNA containing both tRNA sequences. Neither tRNA sequence in the precursor RNA contains the 3'-terminal C-C-A common to all mature tRNAs. Seidman and McClain ((1975) Proc. Natl. Acad. Sci. U. S. A. 72, 1491-1495) have proposed that the C-C-A sequence is added to serine tRNA while it is still part of the large precursor RNA. In the present work, I show that, in vitro, a purified preparation of Escherichia coli tRNA nucleotidyltransferase (EC 2.7.7.25) accurately synthesized 3'-terminal C-C-A in the serine tRNA portion of the precursor RNA. This result establishes a role of tRNA nucleotidyltransferase in the biosynthesis of the phage T4 serine tRNA. The finding that tRNA nucleotidyltransferase utilizes the large precursor RNA as a substrate represents a novel function of the enzyme.

Adenine Nucleotides↗
PubMed1980

Formylmethionyl-tRNA alters RNA polymerase specificity.

Escherichia coli fMet-tRNAfMet alters the pattern of promoter selection of E. coli RNA polymerase (RNA nucleotidyltransferase, nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6), affecting RNA synthesis from the rRNA, suIII+tRNA, and lac promoters in different ways. The in vitro synthesis of the stable RNA species is selectively decreased, whereas that of lac RNA from both the wild-type and mutant UV5 promoters is selectively increased at high ionic strength. The functional effect of fMet-tRNAfMet resembles that of the nucleotide guanosine 3'-diphosphate 5'-diphosphate (ppGpp). This nucleotide competes with the binding of fMet-tRnafMet to RNA polymerase.

Binding, Competitive↗
PubMed1975

Dissociation of two polypeptide chains from yeast RNA polymerase A.

Yeast RNA polymerase A (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) can be converted to a new form of enzyme, called RNA polymerase A*, which is lacking two polypeptide chains of 48,000 and 37,000 daltons. Apart from these two missing polypeptides the subunit structures of RNA polymerases A and A* are indistinguishable. RNA polymerase A* differs from the complete enzyme in its electrophoretic and chromatographic behavior, template requirements, and alpha-amanitin sensitivity. RNA polymerase A* transcribes the alternated copolymer d(A-T)n with the same efficiency as RNA polymerase A but its specific activity is greatly reduced with native calf thymus DNA as template. The transcription of a variety of synthetic templates is also altered by removal of the two polypeptide chains. RNA polymerase A* is inhibited by high concentrations of alpha-amanitin (500 mug/ml), whereas RNA polymerase A is comparatively less sensitive to the toxic peptide. The data are discussed in terms of possible roles of the two dissociable polypeptides.

Amanitins↗
PubMed1975

Chromatin directed transcription of 5S and tRNA genes.

Chromatin prepared by gentle methods from mouse myeloma cells retained its ability to synthesize RNA using bound endogenous RNA polymerase (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6). The transcription resembles that observed in vivo in several respects. The low-molecular-weight RNA species 5S RNA and the 4.5S precursor to 4S RNA, are transcribed accurately and transcription is reinitiated continually in vitro. Their synthesis was not inhibited by alpha-amanitin (1 mug/ml) as was found previously for these species in isolated nuclei.

Animals↗
PubMed1975

Effects of estrogen on gene expression in chick oviduct: nuclear receptor levels and initiation of transcription.

Estrogen (diethylstilbesterol) was administered in vivo to chicks for various time periods. Chromatin was then prepared from oviduct nuclei and assayed for its capacity to support initiation of RNA chain synthesis in vitro in the presence of saturating levels of Escherichia coli RNA polymerase (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6). These same nuclei were also assayed by a [3H]estradiol exchange assay for their endogenous receptor content. The number of available initiation sites for RNA synthesis on chromatin was shown to correlate with the endogenous levels of nuclear estrogen receptor. A decrease in the nuclear concentration of estrogen receptor molecules and the concentration of initiation sites for RNA synthesis occurred during withdrawal of estrogen from previously stimulated chicks. Both parameters declined with a similar half-life. When estrogen was readministered to withdrawn chicks, the number of initiation sites increased 2-fold as early as 30 min and approached a maximal level (3-fold) by 1 hr. During the same period of restimulation with estrogen, the number of estrogen receptor molecules bound to nuclei increased to a maximum at 20 min and then declined at 1 hr to a steady-state level 2-fold higher than the withdrawn chicks. Simultaneous measurements of RNA chain length and RNA chain propagation rate demonstrated that parameters remained relatively constant throughout estrogen withdrawal as well as secondary stimulation. The temporal correlation between changes in the levels of nuclear-bound estrogen receptor and the number of RNA chain initiation sites on chromatin prepared from these same nuclei strongly suggested that the hormone receptor complexes act on chromatin to mediate these changes in genetic transcriptional activity.

Animals↗
PubMed1976

Purification and characterization of a putative sigma factor from Chalamydomonas reinhardi.

Two proteins with sigma-like activity have been isolated from the alga, Chlamydomonas reinhardi. One protein, sigma 2, has been partially purified and appears to have a molecular weight of 51,000. The interaction of this protein with a heterologous (Escherichia coli) and homologous (Chlamydomonas, chloroplast rifampicin-sensitive) core RNA-polymerase (RNA nucleotidyltransferase, nucleosidetriphosphate: RNA nucleotidyltransferase, EC 2.7.7.6) was studied. Sigma 2 protein appears to stimulate the formation of open (rapid starting) binary complexes by both of the core enzymes. Stimulation of transcription by sigma 2 on chloroplast DNA was greater when Chlamydomonas core enzyme was used. Moreover, in vitro transcription on a variety of templates using RNA polymerases I and II from Chlamydomonas was not stimulated by this protein.

Chlamydomonas↗
PubMed1977

Interaction between mutations of ribosomes and RNA polymerase: a pair of strA and rif mutants individually temperature-insensitive but temperature-sensitive in combination.

A temperature-sensitive lethal mutant of Escherichia coli has been constructed by combining two temperature-insensitive mutations: a rif180 mutation that modifies RNA polymerase (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) and a strA24 mutation that modifies the ribosomal protein S12. The temperature sensitivity is a property of the combination of these two particular alleles; replacement of either of the alleles relieves the temperature sensitivity. An isogenic strain containing a different strA mutation (i.e., rif180 strA11) is not temperature sensitive. Evidently ribosomes modified by the particular strA24 polymerase altered by the rif180 mutation, which suggests that in vivo there may exist some interaction between structures of ribosomes and the RNA polymerase.

Bacterial Proteins↗
PubMed1976

Induction of sigma factor synthesis in Escherichia coli by the N gene product of bacteriophage lambda.

Thermoinduction of cells of E. coli carrying prophage lambdacI857 within the bfe gene brings about not only "escape synthesis" of core subunits of the DNA-dependent RNA polymerase (RNA nucleotidyltransferase, nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2-7-7-6), but also a striking stimulation of sigma factor synthesis. The latter phenomenon, termed sigma induction, is generally observed after lambda phage infection or prophage induction. A series of experiments with various bacterial and phage strains led us to conclude that the N gene product of lambda is directly involved to the sigma induction. These and other results obtained with mutants defective in transcription termination factor rho suggest the involvement of a rho-sensitive site in the control of sigma gene expression in E. coli.

Chromosome Mapping↗
PubMed1976

Regulation of transcription factor rho and the alpha subunit of RNA polymerase in Escherichia coli B/r.

Transcriptional termination factor rho, the alpha subunit of RNA polymerase (RNA nucleotidyltransferase nucleosidetriphosphate: RNA nucleotidyltransferase, EC 2.7.7.6), and ribosomal protein S6 were resolved from whole-cell extracts of E. coli B/r by a high-resolution, two-dimensional polyacrylamide gel electrophoretic technique, and were identified through coelectrophoresis with the purified proteins. The regulation of rho, alpha, and S6 was studied, in steady-state cultures of E. coli B/r growing at rates ranging from 0.6 to 2.1 generations per hr, through the use of this gel technique and a double radioisotope labeling procedure. The regulatory patterns of rho and alpha are distinct from, but similar to, one another. Neither rho nor alpha shows the sharply increasing levels with increasing growth rate shown by the ribosomal proteins was exemplified by S6. The difference between the levels of rho and alpha, on the one hand, and S6, on the other, is most pronounced during rapid growth. The regulatory pattern of alpha is interesting, given the recent suggestion that the gene coding for alpha is contranscribed with genes coding for ribosomal proteins.

Bacterial Proteins↗