• Title/Summary/Keyword: tRNA

Search Result 1,843, Processing Time 0.026 seconds

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
    • Proceedings of the Korean Society for Bioinformatics Conference
    • /
    • 2004.11a
    • /
    • pp.77-85
    • /
    • 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.

  • PDF

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
    • /
    • v.5 no.3
    • /
    • pp.289-295
    • /
    • 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.

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

  • 김한복;강창원
    • Korean Journal of Microbiology
    • /
    • v.27 no.4
    • /
    • pp.317-322
    • /
    • 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.

  • PDF

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

  • Park, Soo-Je
    • Korean Journal of Microbiology
    • /
    • v.55 no.3
    • /
    • pp.278-279
    • /
    • 2019
  • Miniimonas arenae KCTC $19750^T$ belonging to family Beutenbergiaceae of the phylum Actinobacteria was isolated from sea sand. I report here the draft genome sequence of strain KCTC $19750^T$. The draft genome comprises a size of 3,402,690 bp, a mean G + C content of 73.6%, 2,957 coding sequences, 2 ribosomal RNA genes, and 44 transfer RNA genes. Also, we found that genes involved in osmotic stress response were identified in its genome. The availability of the genome sequences will provide a more understanding of strain KCTC $19750^T$ as a unique member of the genus Miniimonas.

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
    • /
    • v.3 no.2
    • /
    • pp.135-142
    • /
    • 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.

  • PDF

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
    • /
    • v.11 no.5
    • /
    • pp.420-424
    • /
    • 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
    • Proceedings of the Korea Crystallographic Association Conference
    • /
    • 2003.05a
    • /
    • pp.17-17
    • /
    • 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).

  • PDF