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1.
Summary 5S RNA from B. stearothermophilus and E. coli was reacted with NaIO4 and aniline to remove their 3 terminal nucleoside. These modified 5S RNA molecules were then incorporated in B. stearothermophilus 50 S ribosomal subunits and tested for biological activities. 50 S ribosomes containing the modified 5S RNAs exhibited full activity and we therefore conclude, that the 3 terminus of 5S RNA does not play an active role in protein synthesis. 相似文献
2.
Donald J. Cummings Joanne M. Domenico James Nelson Mitchell L. Sogin 《Journal of molecular evolution》1989,28(3):232-241
Summary DNA sequence analysis and the localization of the 5 and 3 termini by S1 mapping have shown that the mitochondrial (mt) small subunit rRNA coding region fromPodospora anserina is 1980 bp in length. The analogous coding region for mt rRNA is 1962 bp in maize, 1686 bp inSaccharomyces cerevisiae, and 956 bp in mammals, whereas its counterpart inEscherichia coli is 1542 bp. TheP. anserina mt 16S-like rRNA is 400 bases longer than that fromE. coli, but can be folded into a similar secondary structure. The additional bases appear to be clustered at specific locations, including extensions at the 5 and 3 termini. Comparison with secondary structure diagrams of 16S-like RNAs from several organisms allowed us to specify highly conserved and variable regions of this gene. Phylogenetic tree construction indicated that this gene is grouped with other mitochondrial genes, but most closely, as expected, with the fungal mitochondrial genes. 相似文献
3.
Summary The nucleotide sequence of cytoplasmic 5S ribosomal RNA fromEuglena gracilis has been determined to be: G-
A
C
-G-U-A-C-G-G-C-C-A-U-A-C-U-A-C-C-G-G-G-A-A-U-A-C-A-C-C-U-G-A-A-C-C-C-G--U-C-G-A-U-U-U-C-A-G-A-A-G-U-U-A-A-G-C-C-G-G-G-U-U-A-G-G-C-C-C-A-G-U-U-A-G-U-A-C-U-G-A-G-U-G-G-G-C-G-A-C-C-A-C-U-U-G-G-G-A-A-C-A-C-U-G-G-G-U-G-C-U-G-U-A-C-G-C-U-Up. This RNA is 119 nucleotides long and the sequence of a probable tRNA-binding site is GAUU (position 41–44 from the 5-terminus), which is the same as that of a trypanosoma species,Crithidia fasci-culata. TheEuglena 5S rRNA has a pseudouridine residue at position 38 and 3-terminus is phosphorylated. The 5S rRNA sequence ofEuglena resembles those of several other protozoa and higher animals rather than plants.On leave from Department of Zoology, Hiroshima University, Hiroshima, Japan 相似文献
4.
Summary 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 Scherichia coli 16S rRNA gene. The 16S rRNA sequence of M. capricolum reveals 74% and 76% identity 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. 相似文献
5.
There are at least six small stable RNAs inMycoplasma capricolum cells besides tRNAs and rRNAs. One of them, MCS5 RNA, is a homolog of RNase P RNA. The predicted secondary structure of this RNA is essentially the same as that of other eubacterial RNase P RNAs. MCS5 RNA is more similar to the RNase P RNA ofB. subtilis than to that ofE. coli. This is consistent with previous conclusions that mycoplasmas are phylogenetically related to the low G+C Gram-positive bacterial group. The major substrates for MCS5 RNA must be the precursors of tRNAs. The precursor of MCS6 RNA, which is a homolog of theE. coli 10Sa RNA, may also be a substrate for the MCS5 RNA because this RNA has a tRNA-like structure at its 5 and 3 ends. 相似文献
6.
Phylogeny of the 5S ribosomal RNA from Synechococcus lividus II: the cyanobacterial/chloroplast 5S RNAs form a common structural class 总被引:2,自引:0,他引:2
The complete nucleotide sequence of the 5S ribosomal RNA from the cyanobacterium Synechococcus lividus II has been determined. The sequence is (sequence in text) This 5S RNA has the cyanobacterial- and chloroplast-specific nucleotide insertion between positions 30 and 31 (using the numbering system of the generalized eubacterial 5S RNA) and the chloroplast-specific nucleotide-deletion signature between positions 34 and 39. The 5S RNA of S. lividus II has 27 base differences compared with the 5S RNA of the related strain S. lividus III. This large difference may reflect an ancient divergence between these two organisms. The electrophoretic mobilities on nondenaturing polyacrylamide gels of renatured 5S RNAs from S. lividus II, S. lividus III, and spinach chloroplasts are identical, but differ considerably from that of Escherichia coli 5S RNA. This most likely reflects differences in higher-order structure between the 5S RNA of E. coli and these cyanobacterial and chloroplast 5S RNAs. 相似文献
7.
Summary Tobacco chloroplasts were found to contain three species of 5S RNA with different electrophoretic mobility. The nucleotide sequences of two species of the 5S RNA have been determined. The large 5S RNA species (5S RNAL) is composed of 121 nucleotides and the small 5S RNA species (5S RNAs) of 119 nucleotides. The 5S RNAL contains and extra uridine residue at both 5 and 3ends of the 5S RNAs. 相似文献
8.
Direct evidence has been obtained for the presence of adenosine-3:5-cyclic monophosphate (cAMP) in tobacco (Nicotiana tabacum L.) callus tissue cultures, bean (Phaseolus vulgaris L.) seedlings and immature kernels of sweet corn (Zea mays L.) through the use of a highly specific and sensitive gas chromatography-mass spectrometric assay. Levels of endogenous cAMP ranged from 70 to 126 pmol/g fresh weight. Corresponding levels of cAMP determined for the same samples using radioimmunoassay were consistently three to four times higher. Contrary to previous reports for citrus plants, measurable levels of cAMP could not be detected in young lemon leaves within the limits of detection of the mass-spectrometric assay method. In the case of tobacco callus tissue, the coumarin glucoside, scopolin, which was present in large amounts and showed similar chromatographic behaviour to cAMP, interferred strongly with the mass-spectrometric measurements of cAMP in inadequately purified extracts. The use of high-performance liquid chromatography, in addition to standard chromatographic purification methods, produced highly purified plant extracts for quantitation of cAMP and also provided a method for the separation of cAMP from its 2:3-isomer.Abbreviations cAMP
adenosine-3:5-cyclic monophosphate
- 2:3-cAMP
adenosine-2:3-cyclic monophosphate
- GC-MS-MID
combined gas chromatography-mass spectrometry with selected multiple-ion-detection
- HPLC
high-performance liquid chromatography
- RIA
radioimmunoassay
- TLC
thin-layer chromatography 相似文献
9.
D Richter 《Molecular & general genetics : MGG》1980,178(2):325-327
Summary The spoT gene product from Escherichia coli, the guanosine 3,5-bis(diphosphate) 3-pyrophosphohydrolase [ppGppase] catalyzes the specific release of pyrophosphate from the 3-position of guanosine 3,5-bis(diphosphate) [ppGpp]; this reaction is significantly inhibited in the presence of uncharged tRNA
yeast
Phe
. Little or no inhibition is observed with Phe-tRNAPhe, tRNAPhe-CpCpAoxi-red or ribosomal RNA (16S and 23S). 相似文献
10.
Summary Single-strand-specific nuclease S1 was employed as a structural probe to confirm locations of unpaired nucleotide bases in 5S rRNAs purified from prokaryotic species of rRNA superfamily I. Limited nuclease S1 digests of 3- and 5-end-labeled [32P]5S rRNAs were electrophoresed in parallel with reference endoribonuclease digests on thin allel with reference endoribonuclease digests on thin sequencing gels. Nuclease S1 primary hydrolysis patterns were comparable for 5S rRNAs prepared from all 11 species examined in this study. The locations of base-paired regions determined by enzymatic analysis corroborate the general features of the proposed universal five-helix model for prokaryotic 5S rRNA, although the results of this study suggest a significant difference between prokaryotic and eukaryotic 5S rRNAs in the evolution of helix IV. Furthermore, the extent of base-pairing predicted by helix IV needs to be reevaluated for eubacterial species. Clipping patterns in helices II and IV appear to be consistent with a secondary structural model that undergoes a conformational rearrangement between two (or more) structures. Primary clipping patterns in the helix II region, obtained by S1 analysis, may provide useful information concerning the tertiary structure of the 5S rRNA molecule. 相似文献
11.
We have isolated and sequenced one intergenic region and a small part of the flanking regions (18S and 26S rRNA coding regions) of the rRNA-encoding genes (rDNA) from the sea urchinParacentrotus lividus. This region is about 3.8 Kb long. Northern blot hybridizations and S1 mapping experiments demonstrated the presence of a partially processed 21S rRNA precursor which has the same 5 terminus as the 32S primary precursor, also in developmental stages characterized by a low rate of rRNA synthesis.Abbreviations bp
base pair(s)
- Kb
Kilobase(s) or 1000 bp
- nt
nucleotide(s)
- rDNA
DNA encoding rRNA
- rRNA
ribosomal RNA
- S
sedimentation constant 相似文献
12.
ArelA+ strain ofE. coli with four amino acid requirements was starved separately for each amino acid, after which the levels of polysomes, guanosine-5-diphosphate-3-diphosphate and the residual net synthesis of RNA were determined. The polysome level and guanosine-5-diphosphate-3-diphosphate production were coordinately affected by starvation for the different amino acids, whereas no correlation was found between these two parameters and residual RNA synthesis. The main conclusion stemming from these results is that guanosine-5-diphosphate-3-diphosphate cannot act as the sole effector molecule in stringent control of RNA synthesis. 相似文献
13.
Rob Benne 《Molecular biology reports》1992,16(4):217-227
Guide RNAs are encoded in maxicircle and minicircle DNA of trypanosome mitochondria. They play a pivotal role in RNA editing, a process during which the nucleotide sequence of mitochondrial RNAs is altered by U-insertion and deletion. Guide RNAs vary in length from 35 to 78 nucleotides, which correlates with the variation in length of the three functionally important regions of which they are composed: (i) a 4–14 nucleotide anchor sequence embedded in the 5 region, which is complementary to a target sequence on the pre-edited RNA downstream of an editing domain, (ii) a middle part containing the editing information, which ranges from guiding the insertion of just one U into one site to that of the insertion of 32 Us into 10 sites, and (iii) a 5–24 nucleotide 3 terminal oligo [U] extension. Moreover, a variable uridylation site creates gRNAs containing a varying segment of editing information for the same domain. Comparison of different guide RNAs demonstrates that, besides the U-tail, they have no obvious common primary and secondary sequence motifs, each particular sequence being unique. The occurrence in vivo and the synthesis in vitro of chimeric molecules, in which a guide RNA is covalently linked through its 3 U-tail to an editing site of a pre-edited RNA, suggests that RNA editing occurs by consecutive transesterification reactions and is evidence that the guide RNAs not only provide the genetic information, but also the Us themselves.Abbreviations gRNA
guide RNA 相似文献
14.
RNase P in both prokaryotes and eukaryotes is a ribonucleoprotein that cleaves tRNA precursors to generate the 5 termini of the mature tRNAs. Many patients with autoimmune diseases produce antibodies against a 40 kDa protein (designatedTo orTh antigen) which is an integral component of eukaryotic RNaseP as well as nucleolar 7-2 RNP which is identical to the mitochondrial RNA processing (MRP) RNP. Interestingly, theTo antigen found in human cells and the C5 protein, the only protein component ofE. coli RNaseP, are antigenically related. In this study, we show that a 56 nucleotide-long sequence, corresponding to nucleotides 20–75 near the 5 end of human RNaseP RNA, is sufficient to bind theTo antigen. We previously showed that the humanTo antigen binds to a short distinct structural domain near the 5 end of human 7-2/MRP RNA. There is no obvious primary sequence homology between theTo antigen binding sites in RNaseP RNA and 7-2/MRP RNA; however, these sequences are capable of assuming a similar secondary structure which corresponds to the recently proposed cage structure for RNaseP RNAs and 7-2/MRP RNA (Forster and Altman (1989) Cell 62: 407–409). These data are supportive of the idea that these two RNAs may have evolved from a common progenitor molecule. 相似文献
15.
Summary We have determined the nucleotide sequence of an unlinked 5 S rRNA gene region from a thermophilic archaebacterium, Thermococcus celer. This 5 S rRNA gene is flanked by a single tRNAAsp sequence and appears to be transcribed as part of a very short operon consisting of only two gene sequences. Comparative studies indicate features in the 5 and 3 flanking sequences, which bear similarity with promoter and termination signals in eubacteria, but also reflect unusual features found in at least some archaebacteria. The evolution of this unlinked operon and the unusual features are discussed. 相似文献
16.
Sixteen segments ofArabidopsis thaliana DNA that function as enhancers in transgenic tobacco plants were isolated using the pROA97 enhancer cloning vehicle and library transformation ofNicotiana tabacum. The sequences were compared for AT content, homology, repeated motifs, and expression pattern in transgenicN. tabacum. The sequences were average with respect to the AT content ofA. thaliana DNA. They could be placed into seven homology groups. Five of the sequences are single-copy sequences. The remaining eleven sequences represent two homology groups. Homology Group I contains seven sequences with minor differences. Homology Group II contains four sequences with minor differences. Two repeated motifs were identified (5-CCTCT-3 and 5-AAGGAT-3). Both repeated motifs are found in other plant enhancers, and in the promoter region of the cauliflower mosaic virus 35S gene. In the 35S gene TATA region, the motifs can form two alternative stem-loop structures. The TATATAA sequence is located in the loop region of both stem-loop structures. 相似文献
17.
L. Otten P. De Ruffray P. de Lajudie B. Michot 《Molecular & general genetics : MGG》1996,251(1):99-107
One of the four ribosomal RNA operons (rrnA) from theAgrobacterium vitis vitopine strain S4 was sequenced.rrnA is most closely related to therrn operons ofBradyrhizobium japonicum andRhodobacter sphaeroides and carries an fMet-tRNA gene downstream of its 5S gene, as in the case ofR. sphaeroides. The 16S rRNA sequence of S4 differs from theA. vitis K309 type strain sequence by only one nucleotide, in spite of the fact that S4 and K309 have very different Ti plasmids. The predicted secondary structure of the S4 23S rRNA shows several features that are specific for the alpha proteobacteria, and an unusual branched structure in the universal B8 stem. The 3 ends of the three otherrrn copies of S4 were also cloned and sequenced. Sequence comparison delimits the 3 ends of the four repeats and defines two groups:rrnA/rrnB andrrnC/rrnD. 相似文献
18.
Summary The 5-proximal trp leader RNA segment (about 5S) decays at 2 to 3 times slower rates than the distal trp mRNA sequence. This has been demonstrated by employing the deletion mutants which lack a large portion of the structural genes but retain the promoter-proximal region of the trp operon. Relative stability of the leader RNA is not merely due to the presence of an untranslatable region in the segment; the internal untranslatable segment of trp mRNA downstream from the nonsense alteration site of a double mutant trpAD28·trpE9758 decays as fast as the normal trp mRNA sequence. These results suggest that the trp mRNA is endonucleolytically cleaved to yield the small 5-proximal leader RNA segment before the distal mRNA decays and that the leader RNA sequence is not subject to usual mode of mRNA decay in the 5 to 3 direction. 相似文献
19.
G. William Demers Michael J. Matunis Ross C. Hardison 《Journal of molecular evolution》1989,29(1):3-19
Summary The L1 family of long interspersed repetitive DNA in the rabbit genome (L1Oc) has been studied by determining the sequence of the five L1 repeats in the rabbit -like globin gene cluster and by hybridization analysis of other L1 repeats in the genome. L1Oc repeats have a common 3 end that terminates in a poly A addition signal and an A-rich tract, but individual repeats have different 5 ends, indicating a polar truncation from the 5 end during their synthesis or propagation. As a result of the polar truncations, the 5 end of L1Oc is present in about 11,000 copies per haploid genome, whereas the 3 end is present in at least 66,000 copies per haploid genome. One type of L1Oc repeat has internal direct repeats of 78 bp in the 3 untranslated region, whereas other L1Oc repeats have only one copy of this sequence. The longest repeat sequenced, L1Oc5, is 6.5 kb long, and genomic blot-hybridization data using probes from the 5 end of L1Oc5 indicate that a full length L1Oc repeat is about 7.5 kb long, extending about 1 kb 5 to the sequenced region. The L1Oc5 sequence has long open reading frames (ORFs) that correspond to ORF-1 and ORF-2 described in the mouse L1 sequence. In contrast to the overlapping reading frames seen for mouse L1, ORF-1 and ORF-2 are in the same reading frame in rabbit and human L1s, resulting in a discistronic structure. The region between the likely stop codon for ORF-1 and the proposed start codon for ORF-2 is not conserved in interspecies comparisons, which is further evidence that this short region does not encode part of a protein. ORF-1 appears to be a hybrid of sequences, of which the 3 half is unique to and conserved in mammalian L1 repeats. The 5 half of ORF-1 is not conserved between mammalian L1 repeats, but this segment of L1Oc is related significantly to type II cytoskeletal keratin. 相似文献
20.
RNA- synthesis inAcetabularia 总被引:2,自引:0,他引:2
Summary Incorporation of precursors of RNA into the enucleated cells ofAcetabularia mediterranea andPolyphysa cliftonii has been studied under conditions which exclude the possibility of errors due to contamination of the preparations by nuclei, nuclear debris or microorganisms.Radioactive RNA has been isolated from the chloroplast, mitochondrial and supernatant cytoplasm fractions of nucleated and enucleated cells. Sucrose density gradient centrifugation of the isolated labelled RNA produces a sedimentation profile of radioactivity which is similar to that of RNA isolated fromE. coli ribosomes.Anion exchange chromatography of alkaline hydrolysates of the 23 s and 16 s ribosomal RNA fractions shows incorporation of labelled uracil into RNA in the form of 2(3)-UMP and 2(3)-CMP. Labelled guanosine is incorporated only as 2(3)-GMP.A slowly sedimenting radioactivity peak has been chromatographed on a Hershey column and found to correspond to cold t-RNA.Some of the results were presented at the Symposium on Some Biological Systems at the Molecular Level organized by the International Organization for Pure and Applied Biophysics in Naples in September, 1965. 相似文献