• 제목/요약/키워드: tRNA

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AU-rich elements (ARE) found in the U-rich region of Alu repeats at 3' untranslated regions

  • An, Hyeong-Jun;Lee, Kwang-Hyung;Bhak, Jong-Hwa;Lee, Do-Heon
    • 한국생물정보학회:학술대회논문집
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    • 한국생물정보시스템생물학회 2004년도 The 3rd Annual Conference for The Korean Society for Bioinformatics Association of Asian Societies for Bioinformatics 2004 Symposium
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    • pp.77-85
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    • 2004
  • A significant portion (about 8% in human genome) of mammalian mRNA sequences contains AU(Adenine and Uracil) rich elements or AREs at their 3' untranslated regions (UTR). These mRNA sequences are usually stable. ARE motifs are assorted into three classes. The importance of AREs in biology is that they make certain mRNA unstable. We analyzed the occurrences of AREs and Alu, and propose a possible mechanism on how human mRNA could acquire and keep A REs at its 3' UTR originated from Alu repeats. Interspersed in the human genome, Alu repeats occupy 5% of the 3' UTR of mRNA sequences. Alu has poly-adenine (poly-A) regions at the end that lead to poly -thymine (poly-T) regions at the end of its complementary Alu. It has been discovered that AREs are present at the poly -T regions. In the all ARE's classes, 27-40% of ARE repeats were found in the poly -T region of Alu with mismatch allowed within 10% of ARE's length from the 3' UTRs of the NCBI's reference m RNA sequence database. We report that Alu, which has been reported as a junk DNA element, is a source of AREs. We found that one third of AREs were derived from the poly -T regions of the complementary Alu.

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VaSpoU1 (SpoU gene) may be involved in organelle rRNA/tRNA modification in Viscum album

  • Ahn, Joon-Woo;Kim, Suk-Weon;Liu, Jang-Ryol;Jeong, Won-Joong
    • Plant Biotechnology Reports
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    • 제5권3호
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    • pp.289-295
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    • 2011
  • The SpoU family of proteins catalyzes the methylation of transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs). We characterized a putative tRNA/rRNA methyltransferase, VaSpoU1 of the SpoU family, from Viscum album (mistletoe). VaSpoU1 and other plant SpoU1s exhibit motifs of the SpoU methylase domain that are conserved with bacterial and yeast SpoU methyltransferases. VaSpoU1 transcripts were detected in the leaves and stems of V. album. VaSpoU1-GFP fusion proteins localized to both chloroplasts and mitochondria in Arabidopsis protoplasts. Sequence analysis similarly predicted that the plant SpoU1 proteins would localize to chloroplasts and mitochondria. Interestingly, mitochondrial localization of VaSpoU1 was inhibited by the deletion of a putative N-terminal presequence in Arabidopsis protoplasts. Therefore, VaSpoU1 may be involved in tRNA and/or rRNA methylation in both chloroplasts and mitochondria.

T7 발현체계에서 chloramphenicol acetyltransferase의 선택적 과잉생산 (Selective overproduction of chloramphenicol acetyltransferase in the T7 expression system)

  • 김한복;강창원
    • 미생물학회지
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    • 제27권4호
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    • pp.317-322
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    • 1989
  • A gene can be selectively overexpressed in E. coli by utilizing the phage T7 RNA polymerase's stringent recognition and active transcription of the T7 promoter. The T7 expression system was constructed such that the T7 RNA polymerase gene is under the control of lacUV5 promoter in one plasmid, and that the target gene, the promoterless chloramphenicol acetyltransferase (CAT) gene with E. coli ribosome binding site is under the control of T7 promoter in the other plasmid. Only the E. coli cells containing both plasmids show high resistance to chloramphenicol. When the copy number of the runaway plasmid containing the polymerase gene was varied by a temperature shift, amounts of the CAT protein synthesized upon induction was correspondingly changed as shown in SDS gel electrophoresis.

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해양모래로부터 분리된 Miniimonas arenae KCTC 19750T의 유전체 분석 (Draft genome sequence of Miniimonas arenae KCTC 19750T isolated from sea sand)

  • 박수제
    • 미생물학회지
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    • 제55권3호
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    • pp.278-279
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    • 2019
  • Actinobacteria 문 Beutenbergiaceae 과에 속하는 Miniimonas arenae KCTC $19750^T$는 해양모래에서 분리되었다. 본 연구에서는 KCTC $19750^T$의 비완전 유전체를 보고한다. 본 유전체는 3,402,690 bp의 크기와 73.6%의 평균 G + C 함량을 지니고 있으며, 2,947개의 단백질 코딩 유전자, 2개의 ribosomal RNA 및 44개의 transfer RNA로 구성되어 있다. 또한, 삼투압과 관련된 유전자를 포함하고 있다. 본 유전체 서열의 가용성은 Miniimonas 속의 유일한 구성원으로KCTC $19750^T$에 대한 더 많은 이해를 제공할 것이다.

Effect of Testosterone on the mRNA Levels of Gonadotropin Subunits in the Immature Rainbow Trout Pituitary

  • Kim Dae-Jung;Aida Katsumi
    • Fisheries and Aquatic Sciences
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    • 제3권2호
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    • pp.135-142
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    • 2000
  • In order to clarify the role of gonadal sex steroids in the synthesis of gonadotropin (GTH) subunits in immature rainbow trout, we examined in vitro and in vivo effects of testosterone (T) on the pituitary mRNA levels of GTH I $\beta$, GTH II$\beta$ and a subunits by Northern blot analysis and on the pituitary content levels of GTH I$\beta$ and GTH II$\beta$by radioimmunoassay (RIA). The mRNA levels of the a subunit in T-treated fish were not changed more dramatically than those in control fish both in vivo and in vitro. Interestingly, the mRNA levels of GTH I$\beta$ in T-treated fish were shown to be slightly lower than those in the control fish under these experimental conditions, but no differences were observed in pituitary GTH I$\beta$ contents. In contrast, the mRNA levels and pituitary contents of GTH II$\beta$ subunit were strongly increased by T both in vivo and in vitro. These results demonstrate that the expressions of GTH I$\beta$ and II$\beta$ subunit genes in immatue rainbow trout pituitary are subjected to differential regulation by T.

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Preparation Method for Escherichia coliS30 Extracts Completely Dependent upon tRNA Addition to Catalyze Cell-free Protein Synthesis

  • Ahn, Jin-Ho;Hwang, Mi-Yeon;Oh, In-Seok;Park, Kyung-Moon;Hahn, Geun-Hee;Choi, Cha-Yong;Kim, Dong-Myung
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권5호
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    • pp.420-424
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    • 2006
  • A simple method for depleting E. coliS30 extracts of endogenous tRNA has been developed. An $ethanolamine-Sepharose^{(R)}$ column equilibrated with water selectively captured the tRNA molecules in E. coli S30 extracts. As a result, S30 extracts filtered through this column became completely dependent upon the addition of exogenous tRNA to mediate cell-free protein synthesis reactions. We anticipate that the procedures developed and described will be particularly useful for in vitro suppression reaction studies designed to introduce unnatural amino acids into protein molecules.

CRYSTAL STRUCTURE OF tRNA ($m^1$ G37) METHYLTRANSFERASE

  • Ahn, Hyung-Jun;Lee, Byung-Ill;Yoon, Hye-Jin;Yang, Jin-Kuk;Suh, Se-Won
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2003년도 춘계학술연구발표회
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    • pp.17-17
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    • 2003
  • tRNA (m¹ G37) methyltransferase (TrmD) catalyze s the trans for of a methyl group from S-adenosyl-L-methionine (AdoMet) to G/sup 37/ within a subset of bacterial tRNA species, which have a residue G at 36th position. The modified guanosine is adjacent to and 3' of the anticodon and is essential for the maintenance of the correct reading frame during translation. We have determined the first crystal structure of TrmD from Haemophilus influenzae, as a binary complex with either AdoMet or S-adenosyl-L-homocysteine (AdoHcy), as a ternary complex with AdoHcy/phosphate, and as an apo form. The structure indicates that TrmD functions as a dimer (Figure 1). It also suggests the binding mode of G/sup 36/G/sup 37/ in the active site of TrmD and catalytic mechanism. The N-terminal domain has a trefoil knot, in which AdoMet or AdoHcy is bound in a novel, bent conformation. The C-terminal domain shows a structural similarity to DNA binding domain of trp or tot repressor. We propose a plausible model for the TrmD₂-tRNA₂ complex, which provides insights into recognition of the general tRNA structure by TrmD (Figure 2).

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