• Title/Summary/Keyword: RNA 1 structure

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Mutational Analysis of an Essential RNA Stem-loop Structure in a Minimal RNA Substrate Specifically Cleaved by Leishmania RNA Virus 1-4 (LRV1-4) Capsid Endoribonuclease

  • Ro, Youngtae;Patterson, Jean L.
    • Journal of Microbiology
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    • v.41 no.3
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    • pp.239-247
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    • 2003
  • The LRV1-4 capsid protein possesses an endoribonuclease activity that is responsible for the single site-specific cleavage in the 5' untranslated region (UTR) of its own viral RNA genome and the formation of a conserved stem-loop structure (stem-loop IV) in the UTR is essential for the accurate RNA cleavage by the capsid protein. To delineate the nucleotide sequences, which are essential for the correct formation of the stem-loop structure for the accurate RNA cleavage by the viral capsid protein, a wildtype minimal RNA transcript (RNA 5' 249-342) and several synthetic RNA transcripts encoding point-mutations in the stem-loop region were generated in an in vitro transcription system, and used as substrates for the RNA cleavage assay and RNase mapping studies. When the RNA 5' 249-342 transcript was subjected to RNase T1 and A mapping studies, the results showed that the predicted RNA secondary structure in the stem-loop region using FOLD analysis only existed in the presence of Mg$\^$2+/ ions, suggesting that the metal ion stabilizes the stem-loop structure of the substrate RNA in solution. When point-mutated RNA substrates were used in the RNA cleavage assay and RNase T1 mapping study, the specific nucleotide sequences in the stem-loop region were not required for the accurate RNA cleavage by the viral capsid protein, but the formation of a stem-loop like structure in a region (nucleotides from 267 to 287) stabilized by Mg$\^$2+/ ions was critical for the accurate RNA cleavage. The RNase T1 mapping and EMSA studies revealed that the Ca$\^$2+/ and Mn$\^$2+/ ions, among the reagents tested, could change the mobility of the substrate RNA 5' 249-342 on a gel similarly to that of Mg$\^$2+/ ions, but only Ca$\^$2+/ ions identically showed the stabilizing effect of Mg$\^$2+/ ions on the stem-loop structure, suggesting that binding of the metal ions (Mg$\^$2+/ or Ca$\^$2+/) onto the RNA substrate in solution causes change and stabilization of the RNA stem-loop structure, and only the substrate RNA with a rigid stem-loop structure in the essential region can be accurately cleaved by the LRV1-4 viral capsid protein.

Secondary Structure for RNA Aptamers Binding to Guanine-Rich Sequence in the 5'-UTR RNA of N-Ras Oncogene

  • Cho, Bongrae
    • Journal of the Korean Chemical Society
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    • v.65 no.2
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    • pp.121-124
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    • 2021
  • RNA molecules which bind to the G-rich sequence in the 5'-UTR RNA which plays an important role in expression of N-ras, were selected. The secondary structures of five selected RNA aptamers including primer sequence were found by the CLC RNA workbench ver. 4.2 program (www.clcbio.com) and investigated with RNA structural probes such as RNase T1 which has specificity for a G in single-stranded region, RNase V1 specific for double strand and nuclease S1 specific for single strand. The generalized secondary structure model was proposed and characterized. It was composed of a central long double strand region flanked by single strand region at both end sides. The double strand region had an internal single-strand region and bulges. The single strand loop in the right side was composed of four or five nucleotides.

Nucleotide Sequence and Secondary Structure of 5S rRNA from Sphingobium chungbukense DJ77

  • Kwon, Hae-Ryong;Kim, Young-Chang
    • Journal of Microbiology
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    • v.45 no.1
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    • pp.79-82
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    • 2007
  • The 58 rRNA gene from Sphingobium chungbukense DJ77 was identified. The secondary structure of the 199-base-long RNA was proposed. The two-base-long D loop was the shortest among all of the known 5S rRNAs. The U19-U64 non-canonical pair in the helix II region was uniquely found in strain DJ77 among all of the sphingomonads.

Effects of Higher-order RNA Structure on Ribosomal Frameshifting Event for the Expression of pol Gene Products of Human T-cell Leukemia Virus Type I (HTLV-l) (Human T-cell leukemia Virus Type I (HTLV-I) 에서 RNA 고차구조가 pol 유전자의 발현에 필요한 Ribosomal Frameshifting 에 미치는 영향)

  • 남석현
    • Korean Journal of Microbiology
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    • v.30 no.6
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    • pp.472-478
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    • 1992
  • Synthesis of the pol gene products of HTLV-I requires rihosomes to shift frame twice in - I direction while translating genome-size mRNA. We havc made a lI1utagcni/cd RNA in which the gag and pro genes are aligned to allow synthe,.is of a largcr amount of the Gag-Pro-Pol polyproteins by a single frameshifting. Using this mutant, wc could examine the questions whether the predicted RNA secondary or tertiary structure downstream of the shift site is operative as a determinant for - I frameshifting. Deletion analysis showed that the stem-loop structure is essential for efficient frameshifting in the pro-pol overlap, but formation of a pseudoknot is less important.

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Designing An Effective siRNA (효과적인 siRNA의 디자인)

  • Gu, Nam-Jin;Jo, Gwang-Hwi
    • Bioinformatics and Biosystems
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    • v.2 no.1
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    • pp.17-23
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    • 2007
  • Shot interfering RNA (siRNA) can be used to silence specific gene expression and have many potential therapeutic applications. However, how to design an effective siRNA is still not clear. Highly effective siRNA has sequence-specific properties which are low G/C content, low internal stability at the sense strand 3'-terminus, sense strand base bias(position 1 is G/C, position 19 is /AU). Recently, mRNA secondary structure playsan important role in RNAi. Target site of siRNA in high-ordered structure (i.e hairpin loop, multi loop) or base pair of many hydrogen bonds dramatically reduce function of siRNA mediated gene silencing. Possible off-target effects of siRNA is detecting from BLAST search.

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Nucleotide Sequence and Secondary Structure of 16S rRNA from Sphingomonas chungbukensis DJ77 (Sphingomonas chungbukensis DJ77의 16S rRNA 염기서열과 이차구조)

  • Lee Kwan-Young;Kwon Hae-Ryong;Lee Won-Ho;Kim Young-Chang
    • Korean Journal of Microbiology
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    • v.41 no.2
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    • pp.125-128
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    • 2005
  • A 16S ribosomal RNA gene from S. chungbukensis DJ77 has been sequenced. This sequence had a length of 1,502 bp and was extended for 29 bp at 5' and for 37 bp at 3' from the partial sequence (1,435 bp) registered in 2000 year. Besides, 1 bp was newly added near to the 3' end. We made the secondary structure of the 16S rRNA based on E. coli model and found four specific regions. We found constant and variable regions in genus Sphingomonas as the result of multiple alignment of 16S rRNA gene sequences from Sphingomonas spp. and S. chungbukensis DJ77. We found a stem loop structure in S. chungbukensis DJ77, which was only discovered in C. jejuni to date. It showed the structural agreement despite the difference of the sequences from the both organisms. Finally, S. chungbukensis DJ77 belonged to cluster II (Sphingobium) group, after the classification using phylogenetic analysis and nucleotide signature analysis.