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B Pace

Publications and source records attributed to B Pace.

At least 37 records · Page 2Linked to original sources
PubMed1988

Sulfur-oxidizing bacterial endosymbionts: analysis of phylogeny and specificity by 16S rRNA sequences.

The 16S rRNAs from the bacterial endosymbionts of six marine invertebrates from diverse environments were isolated and partially sequenced. These symbionts included the trophosome symbiont of Riftia pachyptila, the gill symbionts of Calyptogena magnifica and Bathymodiolus thermophilus (from deep-sea hydrothermal vents), and the gill symbionts of Lucinoma annulata, Lucinoma aequizonata, and Codakia orbicularis (from relatively shallow coastal environments). Only one type of bacterial 16S rRNA was detected in each symbiosis. Using nucleotide sequence comparisons, we showed that each of the bacterial symbionts is distinct from the others and that all fall within a limited domain of the gamma subdivision of the purple bacteria (one of the major eubacterial divisions previously defined by 16S rRNA analysis [C. R. Woese, Microbiol. Rev. 51: 221-271, 1987]). Two host specimens were analyzed in five of the symbioses; in each case, identical bacterial rRNA sequences were obtained from conspecific host specimens. These data indicate that the symbioses examined are species specific and that the symbiont species are unique to and invariant within their respective host species.

Animals↗
PubMed1986

The RNA component of the Bacillus subtilis RNase P. Sequence, activity, and partial secondary structure.

The gene defining the catalytic RNA component of RNase P in Bacillus subtilis 168 was cloned into bacteriophage lambda and plasmid vectors. The nucleotide sequence of the gene and its surroundings was determined from the cloned DNA and by directly sequencing or reverse transcribing the RNase P RNA. The B. subtilis RNase P RNA sequence (400-401 nucleotides) is remarkably different from that of Escherichia coli (377 nucleotides) (Reed, R. E., Baer, M. F., Guerrier-Takada, C., Donis-Keller, H., and Altman, S. (1982) Cell 30, 627-636; Sakamoto, H., Kimura, N., Nagawa, F., and Shimura, Y. (1983) Nucleic Acids Res. 11, 8237-8251). At best the two are less than 50% similar in sequence. To verify that the RNase P RNA gene was analyzed, a modified, putative gene was cloned adjacent to a bacteriophage T7 promoter and various transcripts were tested for RNase P activity. The intact gene transcript, but not fragments, showed full activity. Full catalytic activity was restored upon mixing the fragments. The extensive differences between the B. subtilis and E. coli RNase P RNAs precluded full covariance analysis of secondary structure, but phylogenetically consistent foldings for portions of both molecules could be derived.

Bacillus subtilis↗
PubMed1985

Rapid determination of 16S ribosomal RNA sequences for phylogenetic analyses.

Although the applicability of small subunit ribosomal RNA (16S rRNA) sequences for bacterial classification is now well accepted, the general use of these molecules has been hindered by the technical difficulty of obtaining their sequences. A protocol is described for rapidly generating large blocks of 16S rRNA sequence data without isolation of the 16S rRNA or cloning of its gene. The 16S rRNA in bulk cellular RNA preparations is selectively targeted for dideoxynucleotide-terminated sequencing by using reverse transcriptase and synthetic oligodeoxynucleotide primers complementary to universally conserved 16S rRNA sequences. Three particularly useful priming sites, which provide access to the three major 16S rRNA structural domains, routinely yield 800-1000 nucleotides of 16S rRNA sequence. The method is evaluated with respect to accuracy, sensitivity to modified nucleotides in the template RNA, and phylogenetic usefulness, by examination of several 16S rRNAs whose gene sequences are known. The relative simplicity of this approach should facilitate a rapid expansion of the 16S rRNA sequence collection available for phylogenetic analyses.

Animals↗
PubMed1984

The ribonucleoprotein substrate for a ribosomal RNA-processing nuclease.

The Bacillus subtilis RNase M5 activity, responsible for the endonucleolytic maturation of 5 S rRNA, requires two proteins, alpha and beta. The beta component has been purified to homogeneity and shown to correspond to ribosomal protein BL16. The BL16 protein evidently corresponds functionally to Escherichia coli ribosomal protein EL18, as that latter protein also will complement the B. subtilis alpha protein in the RNase M5 reaction. A filter binding assay for the formation of B. subtilis 5 S rRNA-protein complexes was characterized and used to evaluate the association of BL16 protein with some RNAs. A native precursor of 5 S rRNA, containing extra sequences at both termini of the mature domain, binds the ribosomal protein no better than the mature 5 S rRNA; the precursor sequences do not facilitate that interaction. A model is considered in which the precursor segments facilitate, by refolding, the dissociation of processing products prior to the RNase M5 step. Electrostatic versus nonelectrostatic contributions to the BL16-5 S rRNA complex formation were inspected by analyzing variation in apparent association constants as a function of ionic strength. Electrostatic interactions were seen to contribute approximately 65% to the overall binding energy.

Bacillus subtilis↗
PubMed1984

The catalytic element of a ribosomal RNA-processing complex.

The Bacillus subtilis RNase M5 complex, responsible for the terminal maturation of 5 S rRNA, includes two proteins. One of these proteins is ribosomal protein BL16 (equivalent to Escherichia coli EL18); the other, the alpha component, is required for catalysis. The RNase M5 alpha component has been purified in bulk extensively, and the active polypeptide (Mr approximately 24,000) identified following polyacrylamide gel electrophoresis. Reaction conditions (20-30% dimethyl sulfoxide) are reported which render RNase M5 activity independent of ribosomal protein BL16. This proves that alpha indeed is the catalytic element, the actual RNase M5, which normally attacks a ribonucleoprotein substrate consisting of protein BL16 in complex with the 5 S rRNA precursor. Kinetic analyses of the BL16-dependent and independent reactions suggest that any alpha-BL16 association contributes little to the energetics of the alpha-ribonucleoprotein substrate interaction. It is postulated that the BL16 protein serves as a scaffold, to lock the precursor mRNA into a conformation recognizable by the nuclease.

Bacillus subtilis↗
PubMed1984

The conserved 5 S rRNA complement to tRNA is not required for translation of natural mRNA.

We have tested a putative base-paired interaction between the conserved GT psi C sequence of tRNA and the conserved GAAC47 sequence of 5 S ribosomal RNA by in vitro protein synthesis using ribosomes containing deletions in this region of 5 S rRNA. Ribosomes reconstituted with 5 S rRNA possessing a single break between residues 41 and 42, deletion of residues 42-46, or deletion of residues 42-52 were tested for their ability to translate phage MS2 RNA. Initiator tRNA binding, aminoacyl-tRNA binding, ppGpp synthesis, and miscoding were also tested. All of the measured functions could be carried out by ribosomes carrying the deleted 5 S rRNAs. The sizes and relative amounts of the polypeptides synthesized by MS2 RNA-programmed ribosomes were identical whether or not the 5 S RNA contained deletions. Aminoacyl-tRNA binding and miscoding were essentially unaffected. Significant reduction in ApUpG (but not poly(A,U,G) or MS2 RNA)-directed fMet-tRNA binding and ppGpp synthesis were observed, particularly in the case of the larger (residues 42-52) deletion. We conclude that if tRNA and 5 S rRNA interact in this fashion, it is not an obligatory step in protein synthesis.

Base Composition↗
PubMed1982

Conserved 5S rRNA complement to tRNA is not required for protein synthesis.

The notion that tRNA and 5S rRNA interact through evolutionarily conserved complementary sequences has been tested by nucleolytic modification of the 5S rRNA, using the modified rRNA to reconstitute the large ribosomal subunit, and assaying for poly(uridylic acid)-directed polyphenylalanine synthesis. The 5S rRNA sequence C-G-A-A (residues 43-46) and several residues surrounding it are not essential for protein synthesis.

Base Sequence↗
PubMed1978

Use of T4 RNA ligase to construct model substrates for a ribosomal RNA maturation endonuclease.

RNase M5 of Bacillus subtilis specifically cleaves a 179-nucleotide precursor 5S rRNA to yield mature 5S rRNA (116 nucleotides) and two fragments derived from the termini. Possible recognition elements for RNase M5 within the precursor structure include nucleotide sequences arranged with 2-fold rotational and translational symmetry about the substrate bonds. We have used bacteriophage T4 RNA ligase to construct, from synthetic oligonucleotides and mature or precursor 5S rRNA fragments, test substrates lacking these symmetry elements. The susceptibilities of the artificial substrates to RNase M5 demonstrate that the symmetrically arranged sequences are not used in the RNase M5 interaction with the precursor. Additionally, the synthetic protocols permitted the invention of an acid-soluble assay for RNase M5 and, potentially, other specific endoribonucleases.

Bacillus subtilis↗
PubMed1977

Involvement of precursor-specific segments in the in vitro maturation of Bacillus subtilis precursor 5S ribosomal RNA.

In vitro maturation of precursor 5S ribosomal RNA (p5A) from Bacillus subtilis effected by RNase M5 yields mature 5S RNA (m5, 116 nucleotides), and 3' precursor-specific segment (42 nucleotides), and a 5' precursor-specific segment (21 nucleotides) (Sogin, M.L., Pace, B., and Pace, N.R. (1977), J. Biol. Chem. 252, 1350). Limited digestion of p5A with RNase T2 introduces a single scission at position 60 of the molecule; m5 is cleaved at the corresponding nucleotide residue. The complementary "halves" of the molecules could be isolated from denaturing polyacrylamide gels. The isolated fragments of p5A are not substrates for RNase M5, suggesting that some recognition elements can be utilized by RNase M5 only when presented in double-helical form. In exploring the involvement of the precursor-specific segments in the RNase M5-p5A interaction, substrate molecules lacking the 3' or 5' precursor-specific segment were constructed by reannealing complementary "halves" from p5A and m5 RNA. The artificial substrate lacking the 5'-terminal precursor segment was cleaved very much more slowly than the lacking t' segment; the 5' precursor-specific segment therefore contains one or more components recognized by RNase M5 during its interaction with the p5A substrate.

Bacillus subtilis↗
PubMed1977

Partial purification and properties of a ribosomal RNA maturation endonuclease from Bacillus subtilis.

Data are presented on the partial purification and properties of a 5 S ribosomal RNA maturation nuclease, termed RNase M5, from Bacillus subtillis 168. RNase M5 specifically cleaves 21 and 42 nucleotides, respectively, from the 5' and 3' termini of a 5 S rRNA precursor to yield the mature (116 nucleotides) 5 S rRNA. The cleavage is endonucleolytic with the formation of 5'-phosphoryl and 3'-hydroxyl groups. Enzyme action requires divalent cations, which may be furnished by either certain metals or by polyamines. The activity is separable into two components both of which are required for activity. It appears that the same nuclease excises the 5'- and 3'-terminal segments since preparations lose the capacity to modify the two termini with an identical first order thermal decay rate. Certain features of the rRNA precursor which may be involved in cognitive interaction with RNase M5 are discussed.

Ammonia↗
PubMed1971

Gene dosage for 5S ribosomal ribonucleic acid in Escherichia coli ad Bacillus megaterium.

The number of gene copies for 5S ribosomal ribonucleic acid (rRNA), relative to that for 16 and 23S rRNA, has been determined by deoxyribonucleic acid (DNA)-RNA hybridization for Escherichia coli and Bacillus megaterium. In both cases, the number of 5S rRNA genes equals the number of 16 or 23S rRNA genes. Rapid procedures for preparing extremely highly purified DNA suitable for DNA-RNA hybridization experiments and chemically pure 5S rRNA are described.

Acrylates↗
PubMed1971

Homology of ribosomal ribonucleic acid of Desulfovibrio species with Desulfovibrio vulgaris.

Three species of Desulfovibrio were found to have a high degree of ribosomal ribonucleic acid homology with Desulfovibrio vulgaris. Desulfotomaculum nigrificans, which is also a sulfate-reducing anaerobe, had only 38% ribosomal ribonucleic acid homology with D. vulgaris. The homologies of six other unrelated genera were determined and found to be lower than 50%.

Alcaligenes↗
PubMed1971

Homology of ribosomal ribonucleic acid diverse bacterial species with Escherichia coli and Bacillus stearothermophilus.

Hybridization competition experiments were used to examine the ribosomal ribonucleic acid (rRNA) homologies of 22 bacteria and 3 higher organisms with Escherichia coli and Bacillus stearothermophilus. Although little or no homology was observed with the higher organisms, the bacteria showed a wide range of homologies. Organisms whose rRNA showed closer homology to E. coli rRNA showed less rRNA homology to B. stearothermophilus rRNA and vice versa.

Animals↗