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Cyanobacterial Non-coding RNA
In molecular biology, Cyanobacterial non-coding RNAs are non-coding RNAs which have been identified in species of cyanobacteria. Large scale screens have identified 21 Yfr (cYanobacterial functional RNAs) in the marine cyanobacterium ''Prochlorococcus'' and related species such as ''Synechococcus''. These include the Yfr1 and Yfr2 RNAs. In ''Prochlorococcus'' and ''Synechocystis'', non-coding RNAs have been shown to regulate gene expression. NsiR4, widely conserved throughout the cyanobacterial phylum, has been shown to be involved in nitrogen assimilation control in Synechocystis sp. PCC 6803 and in the filamentous, nitrogen-fixing Anabaena sp. PCC 7120. PsrR1 (photosynthesis regulatory RNA1), formerly known as Syr1 discovered in '' Synechocystis sp PCC 6803,'' is a regulatory factor controlling photosynthetic functions. Interactions between PsrR1 and the ribosome binding regions of several photosynthesis-related mRNAs have been confirmed. In particular, it has been shown th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-coding RNA
A non-coding RNA (ncRNA) is a functional RNA molecule that is not Translation (genetics), translated into a protein. The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene. Abundant and functionally important list of RNAs, types of non-coding RNAs include transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs), as well as small RNAs such as microRNAs, siRNAs, piRNAs, snoRNAs, snRNAs, Extracellular RNA, exRNAs, scaRNAs and the long noncoding RNA, long ncRNAs such as Xist and HOTAIR. The number of non-coding RNAs within the human genome is unknown; however, recent Transcriptomics, transcriptomic and Bioinformatics, bioinformatic studies suggest that there are thousands of non-coding transcripts. Many of the newly identified ncRNAs have not been validated for their function. There is no consensus in the literature on how much of non-coding transcription is functional. Some researchers have argued that many ncRNAs are non-functional (sometimes r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribonuclease E
Ribonuclease E is a bacterial ribonuclease that participates in the processing of ribosomal RNA (9S to 5S rRNA) and the chemical degradation of bulk cellular RNA. Cellular localization RNase E was suggested to be a part of the cell membrane protein complex, as it sediments with ribosomes and crude membranes. Microscopy has localized tagged RNase E to the inner cytoplasmic membrane or a helical cytoskeletal structure closely associated with the inner layer. Protein structure This enzyme contains 1,061 residues and separates into two distinct functional regions, which are a large domain located at the 5’N-terminus and a small domain located at the 3’ C-terminus. While N-terminal half forms a catalytic domain, C-terminal half forms a degradosome scaffolding domain. A metal-binding pocket separates them in the middle of the RNase E protein structure. Although degradosome formation does not play a key role for E. coli growth, the deletion of the C-terminal half has been foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Tuberculosis SRNA
''Mycobacterium tuberculosis'' contains at least nine bacterial small RNA, small RNA families in its genome. The small RNA (sRNA) families were identified through RNomics – the direct analysis of RNA molecules isolated from cell culture, cultures of ''Mycobacterium tuberculosis''. The sRNAs were characterised through Rapid Amplification of cDNA Ends, RACE mapping and Northern blot experiments. Secondary structures of the sRNAs were predicted using Mfold. sRNAPredict2 – a bioinformatics tool – suggested 56 putative sRNAs in ''M. tuberculosis'', though these have yet to be verified experimentally. Hfq protein homologues have yet to be found in ''M. tuberculosis''; an alternative pathway – potentially involving conserved cytosine, C-rich motifs – has been theorised to enable trans-acting sRNA functionality. sRNAs were shown to have important physiology, physiological roles in ''M. tuberculosis''. Overexpression of G2 sRNA, for example, prevented growth of ''M. tuberculosis' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escherichia Coli SRNA
''Escherichia coli'' contains a number of small RNAs located in intergenic regions of its genome. The presence of at least 55 of these has been verified experimentally. 275 potential sRNA-encoding loci were identified computationally using the QRNA program. These loci will include false positives, so the number of sRNA genes in ''E. coli'' is likely to be less than 275. A computational screen based on promoter sequences recognised by the sigma factor sigma 70 and on Rho-independent terminators predicted 24 putative sRNA genes, 14 of these were verified experimentally by northern blotting. The experimentally verified sRNAs included the well characterised sRNAs RprA and RyhB. Many of the sRNAs identified in this screen, including RprA, RyhB, SraB and SraL, are only expressed in the stationary phase of bacterial cell growth. A screen for sRNA genes based on homology to ''Salmonella'' and ''Klebsiella'' identified 59 candidate sRNA genes. From this set of candidate genes, micro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacterial RNA Thermometer
The first cyanobacterial RNA thermometer ( RNAT) Hsp17 was found in the 5'UTR of ''Synechocystis'' heat shock ''hsp17'' mRNA. Further study demonstrated that cyanobacteria commonly use RNATs to control the translation of their heat shock genes. HspA is a homolog of Hsp17 in thermophilic ''Thermosynechococcus elongatus''. Two more thermometers were found in the 5'UTRs of mesophilic cyanobacteria '' A. variabilis'' and ''Nostoc ''Nostoc'', also known as star jelly, troll’s butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch’s jelly, is the most common genus of cyanobacteria found in var ...'' ''sp''. The first RNAT called avashort was shown to regulate translation by masking the AUG translation start site. The second RNAT called avalong, as it has an extended initial hairpin, might involve tertiary interactions and has similarities to the ROSE element. References Non-coding RNA Cis-regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brucella SRNA
Bacterial small RNAs (sRNA) are an important class of regulatory molecules in bacteria such as ''Brucella''. They are often bound to the chaperone protein Hfq, which allows them to interact with mRNA(s). In ''Brucella suis 1330'' RNA sequencing identified a novel list of 33 sRNAs and 62 Hfq-associated mRNAs. In ''Brucella melitensis'' eight novel sRNA genes were identified using bioinformatic and experimental approach. One of them BSR0602 was found to modulate the intracellular survival of ''B. melitensis''. In another large-scale deep sequencing study 1321 sRNAs were identified in ''B. melitensis.'' BSR0441 sRNA was further investigated in this study and shown to play role in the intracellular survival. sRNA BM-sr0117 from ''Brucella melitensis'' was identified and shown to be bound to and cleaved by Bm-RNase III. AbcR and AbcR2 (orthologs of Αr15 RNA, SmrC15 and SmrC16) were studied ''Brucella abortus, B. abortus''. Seven novel sRNAs were validated and their interaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Small RNA
Bacterial small RNAs (bsRNA) are small RNAs produced by bacteria; they are 50- to 500-nucleotide non-coding RNA molecules, highly structured and containing several stem-loops. Numerous sRNAs have been identified using both computational analysis and laboratory-based techniques such as Northern blotting, microarrays and RNA-Seq in a number of bacterial species including ''Escherichia coli'', the model pathogen ''Salmonella'', the nitrogen-fixing alphaproteobacterium ''Sinorhizobium meliloti'', marine cyanobacteria, ''Francisella tularensis'' (the causative agent of tularaemia), ''Streptococcus pyogenes','' the pathogen ''Staphylococcus aureus'''','' and the plant pathogen ''Xanthomonas oryzae pathovar oryzae''. Bacterial sRNAs affect how genes are expressed within bacterial cells via interaction with mRNA or protein, and thus can affect a variety of bacterial functions like metabolism, virulence, environmental stress response, and structure. Origin In the 1960s, the abbreviation sR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus Subtilis BSR SRNAs
In a screen of the ''Bacillus subtilis'' genome for genes encoding ncRNAs, Saito et al. focused on 123 intergenic regions (IGRs) over 500 base pairs in length, the authors analyzed expression from these regions. Seven IGRs termed bsrC, bsrD, bsrE, bsrF, bsrG, bsrH and bsrI expressed RNAs smaller than 380 nt. All the small RNAs except BsrD RNA were expressed in transformed ''Escherichia coli'' cells harboring a plasmid with PCR-amplified IGRs of ''B. subtilis'', indicating that their own promoters independently express small RNAs. Under non-stressed condition, depletion of the genes for the small RNAs did not affect growth. Although their functions are unknown, gene expression profiles at several time points showed that most of the genes except for bsrD were expressed during the vegetative phase (4–6 h), but undetectable during the stationary phase (8 h). Mapping the 5' ends of the 6 small RNAs revealed that the genes for BsrE, BsrF, BsrG, BsrH, and BsrI RNAs are preceded by a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosome
Ribosomes ( ) are macromolecular machines, found within all cells, that perform biological protein synthesis (mRNA translation). Ribosomes link amino acids together in the order specified by the codons of messenger RNA (mRNA) molecules to form polypeptide chains. Ribosomes consist of two major components: the small and large ribosomal subunits. Each subunit consists of one or more ribosomal RNA (rRNA) molecules and many ribosomal proteins (RPs or r-proteins). The ribosomes and associated molecules are also known as the ''translational apparatus''. Overview The sequence of DNA that encodes the sequence of the amino acids in a protein is transcribed into a messenger RNA chain. Ribosomes bind to messenger RNAs and use their sequences for determining the correct sequence of amino acids to generate a given protein. Amino acids are selected and carried to the ribosome by transfer RNA (tRNA) molecules, which enter the ribosome and bind to the messenger RNA chain via an anti-co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
