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Abstract
In eukaryotes, dozens of posttranscriptional modifications are directed to specific nucleotides in ribosomal RNAs (rRNAs) by small nucleolar RNAs (snoRNAs). We identified homologs of snoRNA genes in both branches of the Archaea. Eighteen small sno-like RNAs (sRNAs) were cloned from the archaeon Sulfolobus acidocaldarius by coimmunoprecipitation with archaeal fibrillarin and NOP56, the homologs of eukaryotic snoRNA-associated proteins. We trained a probabilistic model on these sRNAs to search for more sRNAs in archaeal genomic sequences. Over 200 additional sRNAs were identified in seven archaeal genomes representing both the Crenarchaeota and the Euryarchaeota. snoRNA-based rRNA processing was therefore probably present in the last common ancestor of Archaea and Eukarya, predating the evolution of a morphologically distinct nucleolus.
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MESH Headings
- Archaea/genetics
- Archaeal Proteins/genetics
- Base Sequence
- Chromosomal Proteins, Non-Histone/genetics
- Cloning, Molecular
- Genome, Archaeal
- Methylation
- Models, Statistical
- Molecular Sequence Data
- Nuclear Proteins/genetics
- RNA Processing, Post-Transcriptional
- RNA, Archaeal/chemistry
- RNA, Archaeal/genetics
- RNA, Archaeal/metabolism
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- RNA, Small Nucleolar/chemistry
- RNA, Small Nucleolar/genetics
- RNA, Small Nucleolar/metabolism
- Sulfolobus acidocaldarius/genetics
- RNA, Small Untranslated
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Affiliation(s)
- A D Omer
- Department of Biochemistry and Molecular Biology, University of British Columbia, 2146 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
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2
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Kirpekar F, Douthwaite S, Roepstorff P. Mapping posttranscriptional modifications in 5S ribosomal RNA by MALDI mass spectrometry. RNA (NEW YORK, N.Y.) 2000; 6:296-306. [PMID: 10688367 PMCID: PMC1369914 DOI: 10.1017/s1355838200992148] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We present a method to screen RNA for posttranscriptional modifications based on Matrix Assisted Laser Desorption/Ionization mass spectrometry (MALDI-MS). After the RNA is digested to completion with a nucleotide-specific RNase, the fragments are analyzed by mass spectrometry. A comparison of the observed mass data with the data predicted from the gene sequence identifies fragments harboring modified nucleotides. Fragments larger than dinucleotides were valuable for the identification of posttranscriptional modifications. A more refined mapping of RNA modifications can be obtained by using two RNases in parallel combined with further fragmentation by Post Source Decay (PSD). This approach allows fast and sensitive screening of a purified RNA for posttranscriptional modification, and has been applied on 5S rRNA from two thermophilic microorganisms, the bacterium Bacillus stearothermophilus and the archaeon Sulfolobus acidocaldarius, as well as the halophile archaea Halobacterium halobium and Haloarcula marismortui. One S. acidocaldarius posttranscriptional modification was identified and was further characterized by PSD as a methylation of cytidine32. The modified C is located in a region that is clearly conserved with respect to both sequence and position in B. stearothermophilus and H. halobium and to some degree also in H. marismortui. However, no analogous modification was identified in the latter three organisms. We further find that the 5' end of H. halobium 5S rRNA is dephosphorylated, in contrast to the other 5S rRNA species investigated. The method additionally gives an immediate indication of whether the expected RNA sequence is in agreement with the observed fragment masses. Discrepancies with two of the published 5S rRNA sequences were identified and are reported here.
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MESH Headings
- Base Sequence
- Geobacillus stearothermophilus/genetics
- Geobacillus stearothermophilus/metabolism
- Haloarcula marismortui/genetics
- Haloarcula marismortui/metabolism
- Halobacterium salinarum/genetics
- Halobacterium salinarum/metabolism
- Methylation
- Phosphorylation
- RNA Processing, Post-Transcriptional
- RNA, Archaeal/chemistry
- RNA, Archaeal/genetics
- RNA, Archaeal/metabolism
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Ribosomal, 5S/chemistry
- RNA, Ribosomal, 5S/genetics
- RNA, Ribosomal, 5S/metabolism
- Species Specificity
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
- Sulfolobus acidocaldarius/genetics
- Sulfolobus acidocaldarius/metabolism
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Affiliation(s)
- F Kirpekar
- Department of Molecular Biology, Odense University, Denmark.
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3
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Russell AG, Ebhardt H, Dennis PP. Substrate requirements for a novel archaeal endonuclease that cleaves within the 5' external transcribed spacer of Sulfolobus acidocaldarius precursor rRNA. Genetics 1999; 152:1373-85. [PMID: 10430568 PMCID: PMC1460720 DOI: 10.1093/genetics/152.4.1373] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During ribosome biogenesis in the hyperthermophilic archaeon Sulfolobus acidocaldarius, at least three separate precursor endonucleolytic cleavages occur within the 144-nucleotide-long 5' external transcribed spacer (5' ETS) region of the rRNA operon primary transcript. The 5' ETS sequence contains three regions of very stable helical structure. One cleavage (5' to position -98) is in the single-stranded region between the 5' and the central helical domains; a second cleavage (5' to position -31) is in the single-stranded region between the central and the 3' helical domains; and a third cleavage is at the 5' ETS-16S junction (5' to position +1). The three sites share a common consensus sequence around the position of cleavage. We have used an in vitro pre-RNA processing assay to define some of the sequence and structural recognition elements necessary for the two precursor cleavages 5' to positions -98 and -31. Surprisingly, none of the three predominant helical domains are required for recognition or targeting of the cleavages, although their removal reduces the rate of cleavage site utilization. We show that the sequence AAG downward arrow (CA)UU encompassing each site contains at least some of the essential features for recognition and efficient targeting of the cleavages. Cleavage depends on the presence of a purine 5' and a uracil two nucleotides 3' to the scissile phosphodiester bond. Mutations to other bases at these critical positions are either not cleaved or cleaved very poorly. Finally, on the basis of intermediates that are produced during a processing reaction, we can conclude that the cleavages at positions 98 and 31 are not ordered in vitro.
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Affiliation(s)
- A G Russell
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Kusser I, Lowing C, Rathlef C, Köpke AK, Matheson AT. Structure-function relationships in the ribosomal protein L12 in the archaeon Sulfolobus acidocaldarius. Arch Biochem Biophys 1999; 365:254-61. [PMID: 10328820 DOI: 10.1006/abbi.1999.1154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A series of mutant L12 ribosomal proteins was prepared by site-directed mutations in the L12 protein gene of the archaeon Sulfolobus acidocaldarius. The mutant protein genes were overexpressed in Escherichia coli, and the products purified and incorporated into ribosomal cores which had been ethanol extracted to remove wild-type L12 protein. Measurements were made to determine if the mutation affected the binding of the L12 protein to the ribosome core or affected the translational activity of the resulting ribosome. Changing tyrosine [3] or tyrosine [5], conserved in all archaea and present in all eukarya in positions [3] and [7], to phenylalanine had no effect on binding or translational activity while changes to glycine significantly reduced binding and translational activity. Changing the single arginine [37] residue, conserved in almost all archaeal and eukaryal L12 proteins, to lysine, glutamic acid, glutamine, or glycine had no effect on binding to the core and had little or no significant effect on translational activity. The same was true when lysine [39], conserved in all archaeal L12 proteins, was changed to arginine, glutamic acid, glutamine, or glycine. Changing phenylalanine [104], the penultimate amino acid at the C-terminal end, which is conserved in all archaeal and eukaryal L12 proteins, to tyrosine or glycine had no effect on binding but lowered the translational activity by 60 and 75%, respectively, suggesting that this amino acid plays an important role in translation. Deletion of the highly charged region in the C-terminal domain, which is present in all archaeal and eukaryal L12 proteins, decreased transitional activity by 50%, suggesting this region is also involved in factor interactions.
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Affiliation(s)
- I Kusser
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
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5
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Sensen CW, Klenk HP, Singh RK, Allard G, Chan CC, Liu QY, Penny SL, Young F, Schenk ME, Gaasterland T, Doolittle WF, Ragan MA, Charlebois RL. Organizational characteristics and information content of an archaeal genome: 156 kb of sequence from Sulfolobus solfataricus P2. Mol Microbiol 1996; 22:175-91. [PMID: 8899719 DOI: 10.1111/j.1365-2958.1996.tb02666.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have initiated a project to sequence the 3 Mbp genome of the thermoacidophilic archaebacterium Sulfolobus solfataricus P2. Cosmids were selected from a provisional set of minimally overlapping clones, subcloned in pUC18, and sequenced using a hybrid (random plus directed) strategy to give two blocks of contiguous unique sequence, respectively, 100,389 and 56,105 bp. These two contigs contain a total of 163 open reading frames (ORFs) in 26-29 putative operons; 56 ORFs could be identified with reasonable certainty. Clusters of ORFs potentially encode proteins of glycogen biosynthesis, oxidative decarboxylation of pyruvate, ATP-dependent transport across membranes, isoprenoid biosynthesis, protein synthesis, and ribosomes. Putative promoters occur upstream of most ORFs. Thirty per cent of the predicted strong and medium-strength promoters can initiate transcription at the start codon or within 10 nucleotides upstream, indicating a process of initial mRNA-ribosome contact unlike that of most eubacterial genes. A novel termination motif is proposed to account for 15 additional terminations. The two contigs differ in densities of ORFs, insertion elements and repeated sequences; together they contain two copies of the previously reported insertion sequence ISC 1217, five additional IS elements representing four novel types, four classes of long non-IS repeated sequences, and numerous short, perfect repeats.
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Affiliation(s)
- C W Sensen
- Canadian Institute for Advanced Research, Program in Evolutionary Biology, National Research Council of Canada, Halifax, Nova Scotia, Canada
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Kath T, Schäfer G. A secY homologous gene in the crenarchaeon Sulfolobus acidocaldarius. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1264:155-8. [PMID: 7495856 DOI: 10.1016/0167-4781(95)00165-d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The nucleotide sequence of an open reading frame, located upstream of the gene for adenylate kinase, was determined in the thermoacidophile crenarchaeon Sulfolobus acidocaldarius. Data bank searches identified the sequence as a secY homologous gene. The DNA derived protein sequence of total 463 amino acids contains 10 hydrophobic domains. A sequence alignment with other prokaryotic and eukaryotic secY sequences reveals significant homology, but the secY primary sequence of S. acidocaldarius shows only a low degree of similarity with the secY counterparts of the euryarchaea Methanococcus vannielii and Haloarcula marismortui. A transcription analysis indicates, that the secY gene is cotranscribed with the gene coding for adenylate kinase.
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Affiliation(s)
- T Kath
- Institute of Biochemistry, Medical University of Lübeck, Germany
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Moll R, Schmidtke S, Schäfer G. Nucleotide sequence of a gene cluster encoding ribosomal proteins in the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1261:315-8. [PMID: 7711082 DOI: 10.1016/0167-4781(95)00024-b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A 1.6 kb genomic DNA fragment derived from the extremely thermoacidophilic archaeon Sulfolobus acidocaldarius (DSM 639) comprises four open reading frames. The sequence contains three genes encoding crenarchaeal ribosomal proteins with apparent molecular masses of 6.3 kDa, 15.2 kDa and 9.9 kDa, which all represent strongly basic properties. These were identified by sequence comparison as RL46, RL31 and RL33. One open reading frame encodes a new polypeptide (22.1 kDa, pI = 7.3) with no homology to known proteins. The latter is transcribed as a common mRNA with RL46 and RL31. This gene cluster immediately precedes another cluster including genes encoding the putative SRP receptor alpha subunit as well as the putative secEp.
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Affiliation(s)
- R Moll
- Institute of Biochemistry, Medical University of Lübeck, Germany
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Durovic P, Dennis PP. Separate pathways for excision and processing of 16S and 23S rRNA from the primary rRNA operon transcript from the hyperthermophilic archaebacterium Sulfolobus acidocaldarius: similarities to eukaryotic rRNA processing. Mol Microbiol 1994; 13:229-42. [PMID: 7527119 DOI: 10.1111/j.1365-2958.1994.tb00418.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In the hyperthermophilic archaebacterium Sulfolobus acidocaldarius, the mature 16S and 23S rRNA are generated by processing of a 5000-nucleotide transcript. Analysis of intermediates that accumulate in vivo indicates that the transcript contains 11 separate processing sites. The processing and maturation of 23S rRNA appears to follow the typical archaebacterial pathway, utilizing a bulge-helix-bulge motif within the 23S processing helix as the substrate for an excision endonuclease. The precursor 23S rRNA that is released is trimmed at its 5' and 3' ends to generate the mature 23S rRNA found in 50S ribosomal subunits. The pathway for processing and maturation of 16S rRNA is distinctive and does not use the bulge-helix-bulge motif in the 16S processing stem. Instead, the transcript is cleaved at several novel positions in the 5' leader and in the 3' intercistronic sequence. The excised precursor 16S is trimmed at the 5' end but an extra 60 nucleotides of what is normally spacer sequence is retained at the 3' end. The elongated 16S rRNA is present in active 30S subunits. An in vitro processing system for the 16S rRNA has been established. The RNA substrate containing the entire 144-nucleotide 5' leader and the first 72 nucleotides of 16S sequence is cleaved at the same positions observed in vivo by an endonuclease activity present in cell extract. These results demonstrate (i) that the 16S processing helix is neither utilized nor required for leader processing, and (ii) that complete maturation to the 5' end of 16S rRNA can occur in the absence of concomitant ribosome assembly and in the absence of all but the first 72 nucleotides of the 16S rRNA sequence. The endonuclease activity responsible for cleavage of the 5' leader substrate is sensitive to nuclease digestion, suggesting that it contains an essential RNA component. The cleavage sites appear to be located within regions of irregular secondary structure and have a consensus sequence of GAUUCC.
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MESH Headings
- Bacterial Proteins/metabolism
- Base Sequence
- Consensus Sequence
- Endoribonucleases/metabolism
- Eukaryotic Cells/metabolism
- Molecular Sequence Data
- Nucleic Acid Conformation
- Operon
- RNA Precursors/chemistry
- RNA Precursors/metabolism
- RNA Processing, Post-Transcriptional
- RNA, Bacterial/chemistry
- RNA, Bacterial/metabolism
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/metabolism
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/metabolism
- Sulfolobus/genetics
- Sulfolobus/metabolism
- Transcription, Genetic
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Affiliation(s)
- P Durovic
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
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