• Journal of the Korean Chemical Society
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• v.26 no.6
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• pp.396-402
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• 1982

Bacteriophage T4 tRNA processing in E. coli mutant strains defective in RNase Ⅲ, RNase E$^-$, and RNase P, respectively, singly or in combinations, was investigated. In $RNase E^- strains, a RNA band, which would be referred as 9S RNA, accumulates, while in RNase$ P^-$ strains, lower band of 6S double band is accumulated. In RNase III$^-$ strains, the production of tRAN$^{Gln}$ coded by T4 tRNA gene cluster, is severely depressed and also production of species 1 RNA, which is coded by T4 DNA but not by the tRNA gene cluster, is in somewhat depressed amounts; on the other hand, at the same time, an upper band of 6S double bands, coded by T4 tRNA gene cluster, is accumulated in rather greater amounts as compared to the RNase $^+$ strain. The upper band RNA of the 6S double band, however, does not appear to be a precursor to the tRNA$^{Gln}$. The present work points to the lack of evidence for an essential cleavage role of RNase Ⅲ, although there must be a role for the RNase Ⅲ in the T4 tRNA processing.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.237-243
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• 1998

To understand the tissue specific expression pattern of S RNase genes associated with self-incompatibility in L. peruvianum, two promoter regions of $S_{11}$ and $S_{12}$ RNase genes were compared. Homologous sequences between two S RNase gene promoters were found within 300 bp upstream of transcription start site. Moreover short direct repeat sequences within $S_{11}$ RNase gene promoter existed in the vicinity of 350-500 bp upstream of transcription start site. To identify whether the unique promoter sequences of $S_{11}$ RNase gene confer the tissue specific expression, six deletion fragments for $S_{11}$ genomic gene promoter constructed by PCR were fused to $\beta$-glucuronidase gene, and introduced into various tissues of L. peruvianum by microprojectile bombardment. Transient expression assays indicated that $S_{11}$ RNase gene promoter contained the positive and negative regulatory sequences, which can control the floral tissue-specific expression in L. peruvianum.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1100-1105
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• 2005

Previous work has identified a Streptomyces coelicolor gene, rns, encoding a 140 kDa protein (RNase ES) that exhibits the endoribonucleolytic cleavage specificity characteristic of RNase E and confers viability on and allows the propagation of E. coli cells lacking RNase E. Here, we identify a putative S. coelicolor 9S rRNA sequence and sites cleaved by RNase ES. The cleavage of the S. coelicolor 9S rRNA transcript by RNase ES resulted in a 5S rRNA precursor (p5S) that had four and two additional nucleotides at the 5' end and 3' ends of the mature 5S rRNA, respectively. However, despite the similarities between RNase E and RNase ES, these enzymes could accurately process 9S rRNA from just their own bacteria, indicating that these ancient enzymes and the rRNA segments that they attack appear to have co-evolved.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.72-75
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• 2007

Using co-immunoprecipitation, we identified proteins interacting with Streptomyces coelicolor RNase ES, an ortholog of Escherichia coli RNase E that plays a major role in RNA decay and processing. Polyphosphate kinase and a homolog of exoribonuclease polynucleotide phosphorylase, guanosine pentaphosphate synthetase I that use inorganic phophate were co-precipitated with RNase E, indicating a possibility of S. coelicolor RNase ES to form a multiprotein complex called degradosome, which has been shown to be formed by RNase E in E. coli. Polynucleotide phophorylase proteins from these two phylogenetically distantly related bacteria species showed similar RNA cleavage action in vitro. These results imply the ability of RNase ES to form a multiprotein complex that has structurally and functionally similar to that of E. coli degradosome.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.219-226
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• 2000

Lycopersicon peruvianum has a gametophytic self-incompatibility (GSI) mechanism controlled by a single genetic locus (S locus) with multiple alleles. S RNases, an allelic series of abundant stylar proteins, are products of the S locus in L. peruvianum and other Solanaceous plants. The $S_{11}$ RNase gene from L. peruvianum was introduced into a self-compatible (SC) species (Lycopersicon esculentum) to examine whether the expression pattern in the heterologous host mimics that in L. peruvianum. The resultant transgenic L. esculentum plants expressed the introduced gene highly in their styles, which is similar manner to the expresion in L. peruvianum. The $S_{11}$ RNase gene was expressed in the syle at a similar stage of flower development in both transgenic plants of L. esculentum and L. peruvianum without any morphological changes.

• Korean Journal of Microbiology
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• v.44 no.2
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• pp.93-97
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• 2008

RraA is a recently discovered protein inhibitor that regulates the enzymatic activity of RNase E, which plays a major role in the decay and processing of RNAs in Escherichia coli. It has also been shown to regulate the activity of RNase ES, a functional Streptomyces coelicolor ortholog of RNase E, which has 36% identity to the amino-terminal region of RNase E. There are two open reading frames in S. coelicolor genome that can potentially encode proteins having more than 35.4% similarity to the amino acid sequence of RraA. DNA fragment encoding one of these RraA orthologs, designated as RraAS2 here, was amplified and cloned in to E. coli vector to test whether it has ability to regulate RNase E activity in E. coli cells. Co-expression of RraAS2 partially rescued E. coli cells over-producing RNase E from growth arrest, although not as efficiently as RraA, induced by the increased ribonucleolytic activity in the cells. The copy number of ColEl-type plasmid in these cells was also decreased by 14% compared to that in cells over-producing RNase E only, indicating the ability of RraAS2 to inhibit RNase E action on RNA I. We observed that the expression level of RraAS2 was lower than that of RraA by 4.2 folds under the same culture condition, suggesting that because of inefficient expression of RraAS2 in E. coli cells, co-expression of RraAS2 was not efficiently able to inhibit RNase E activity to the level for proper processing and decay of all RNA species that is required to restore normal cellular growth to the cells over-producing RNase E.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.223-227
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• 2010

RNase E plays a major role in the degradation and processing of a large number of RNA transcripts in Escherichia coli and forms the core component of the degradosome, a large protein complex involved in RNA metabolism. RraA and RraB are recently discovered protein inhibitors of RNase E and are evolutionarily conserved. In this study, we observed that, unlike RraA, overexpression of RraB did not rescue growth arrest of E. coli cells overexpressing RNase E. To examine whether this phenomenon stems from differential inhibitory effects of RraA and RraB on RNase E substrates, we analyzed three in vivo RNase E substrates. The results showed that RraA inhibited RNase E activity more efficiently than RraB on the degradation of RNA I, which controls the copy number of ColE1-type plasmid, and rpsO mRNA encoding ribosomal protein S15, while RraB was unable to inhibit the processing of pM1 RNA, a precursor of the RNA component of RNase P, by RNase E. Our results imply that RraB inhibits RNase E activity in a more substrate-dependent manner than RraA and this property of RraB may explain why overexpression of RraB could not rescue cells overexpressing RNase E from growth arrest.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.243-248
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• 2016

RNase E (Rne) is an essential enzyme involved in the processing and degradation of a large portion of RNAs in Escherichia coli. The enzymatic activity of RNase E is controlled by regulators of ribonuclease activity, namely, RraA and RraB. Gram-positive bacterium Streptomyces coelicolor also contains homologs of Rne and RraA, designated as RNase ES (Rns), RraAS1, and RraAS2. In the present study, we investigated the effect of S. coelicolor RraAS1 on the ribonucleolytic activity of RNase E in E. coli. Coexpression of RraAS1 with Rne resulted in the decreased levels of rpsO, ftsZ, and rnhB mRNAs, which are RNase E substrates, and augmented the toxic effect of Rne overexpression on cell growth. These in vivo effects appeared to be induced by the binding of RraAS1 to Rne, as indicated by the results of co-immunoprecipitation analysis. These results suggested that RraAS1 induces ribonucleolytic activity of RNase E in E. coli.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.49-57
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• 2016

We isolated and confirmed two S-RNases, denoted as mpS1 and mpS2, from apple rootstock 'Marubakaido' (Malus prunifolia Borkh. Var. ringo Asami). These S-RNases contained and conserved five cysteine residues and two histidine residues, which are essential for RNase activity. The mpS1 showed high similarity to S5 (99.1%) of Malus spectabilis, whereas the mpS2 showed 99.5% nucleotide sequence similarity to S26 of (Malus ${\times}$ domestica) and 99.6% to S35 of (Malus sieversii) when compared with reported S-RNases. In amino acid sequences, the mpS1-RNase was almost similar to the S5-RNase of Malus spectabilis, and the mpS2-RNase was similar to the S35 of Malus sieversii, with only one bp being different from the S26-RNase of Malus ${\times}$ domestica. The 57 S-RNases of Malus species were renamed and rearranged containing the new S-RNases, as mprpS35 (mpS2) and mprpS57 (mpS1), for determining S-genotypes and identifying new alleles from apple species (Malus spp.).

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.229-232
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• 2010

Enolase is one of the glycolytic enzymes, which are involved in a central energy metabolism present in nearly all organisms. In Escherichia coli, enolase constitutes RNA degradosome with RNase E, PNPase and RNA helicase, which are involved in most mRNA degradation and RNA processing. Recently, it has been reported that RNase G, an RNase E homolog, degrades eno mRNA. To examine a functional role of RNase G in enolase expression which is known to be up-regulated under microaerobic condition, we carried out experiments. Here, we report that expression levels of enolase and RNase G are not correlated under microaerobic condition. Based on this observation, we suggest the existence of an unknown factor(s) which regulate the activity of RNase G or enolase mRNA under microaerobic conditions.