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Mycobacterium Tuberculosis SRNA
''Mycobacterium tuberculosis'' contains at least nine small RNA families in its genome. The small RNA (sRNA) families were identified through RNomics – the direct analysis of RNA molecules isolated from cultures of ''Mycobacterium tuberculosis''. The sRNAs were characterised through 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 C-rich motifs – has been theorised to enable trans-acting sRNA functionality. sRNAs were shown to have important physiological roles in ''M. tuberculosis''. Overexpression of G2 sRNA, for example, prevented growth of ''M. tuberculosis'' and greatly reduced the growth of ''M. smegmatis''; ASdes sRNA is thought to be a cis-a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B55 SScons , an aircraft
{{Letter-NumberCombDisambig ...
B55 may refer to : * Bundesstraße 55, a German road * Karoonda Highway, a road in South Australia * HLA-B55, an HLA-B serotype B-55 may refer to : * Boeing XB-55 Boeing XB-55 (company designation Model 474) was a proposed Boeing aircraft designed to be a strategic bomber. The XB-55 was intended to be a replacement for the Boeing B-47 Stratojet in United States Air Force (USAF) service. Design and devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Reading Frame
In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames will be "open" (the "reading", however, refers to the RNA produced by transcription of the DNA and its subsequent interaction with the ribosome in translation). Such an ORF may contain a start codon (usually AUG in terms of RNA) and by definition cannot extend beyond a stop codon (usually UAA, UAG or UGA in RNA). That start codon (not necessarily the first) indicates where translation may start. The transcription termination site is located after the ORF, beyond the translation stop codon. If transcription were to cease before the stop codon, an incomplete protein would be made during translation. In eukaryotic genes with multiple exons, introns are removed and exons are then joined together after transcription to yield the final ... [...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, microar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteroides Thetaiotaomicron SRNA
The ''Bacteroides thetaiotaomicron'' genome contains hundreds of small RNAs (sRNAs), discovered through RNA sequencing. These include canonical housekeeping RNA species such as the 6S RNA (SsrS), tmRNA (SsrA), M1 RNA (RnpB) and 4.5S RNA (Ffs) as well as several hundred cis and trans encoded small RNAs. More than 20 candidates have been validated with northern blots and the structures of several members have been characterized through ''in silico'' analyses and chemical probing experiments. Two ''B. thetaiotaomicron'' sRNAs that have been functionally characterized are RteR and GibS. RteR is a 78 nucleotide (nt) long sRNA that is conserved in closely related species and likely serves as a repressor of a transposon operon. Analyses based on secondary structure conservation, taking into consideration nucleotide covariation and in-vitro chemical probing have revealed a structure that consists of a 5’ hairpin and a Rho-independent terminator that are separated by an 8 nt seque ... [...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 SmrC15 and SmrC16) were studied '' B. abortus''. Seven novel sRNAs were validated and their interaction with a putative target seq ... [...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 Alphaproteobacteria, 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, t ... [...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 rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twin-arginine Translocation Pathway
The twin-arginine translocation pathway (Tat pathway) is a protein export, or secretion pathway found in plants, bacteria, and archaea. In contrast to the Sec pathway which transports proteins in an unfolded manner, the Tat pathway serves to actively translocate folded proteins across a lipid membrane bilayer. In plants, the Tat translocase is located in the thylakoid membrane of the chloroplast, where it acts to export proteins into the thylakoid lumen. In bacteria, the Tat translocase is found in the cytoplasmic membrane and serves to export proteins to the cell envelope, or to the extracellular space. The existence of a Tat translocase in plant mitochondria is also proposed. In the plant thylakoid membrane and in Gram-negative bacteria the Tat translocase is composed of three essential membrane proteins; TatA, TatB, and TatC. In the most widely studied Tat pathway, that of the Gram-negative bacterium ''Escherichia coli'', these three proteins are expressed from an operon with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic AMP
Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway. History Earl Sutherland of Vanderbilt University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones", especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP). Synthesis Cyclic AMP is synthesized from ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell. Adenylate cyclase is ''activated'' by a range of signaling molecules through the activation of adenylate cyclase stimulatory G ( Gs)-protein-coupled receptors. Adenylate cyclase is ''inhibited'' by agonists of adenylat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Triphosphate
Adenosine triphosphate (ATP) is an organic compound that provides energy to drive many processes in living cells, such as muscle contraction, nerve impulse propagation, condensate dissolution, and chemical synthesis. Found in all known forms of life, ATP is often referred to as the "molecular unit of currency" of intracellular energy transfer. When consumed in metabolic processes, it converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. The human body recycles its own body weight equivalent in ATP each day. It is also a precursor to DNA and RNA, and is used as a coenzyme. From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the Polyphosphate, triphosphate. Structure ATP consists of an adenine attached by the 9-nitrogen atom to the 1′ carbon atom of a sugar (ribose), which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenylyl Cyclase
Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction: :ATP = 3′,5′-cyclic AMP + diphosphate It has key regulatory roles in essentially all cells. It is the most polyphyletic known enzyme: six distinct classes have been described, all catalyzing the same reaction but representing unrelated gene families with no known sequence or structural homology. The best known class of adenylyl cyclases is class III or AC-III (Roman numerals are used for classes). AC-III occurs widely in eukaryotes and has important roles in many human tissues. All classes of adenylyl cyclase catalyse the conversion of adenosine triphosphate (ATP) to 3',5'-cyclic AMP (cAMP) and pyrophosphate.Magnesium ions are generally required and appear to be closely involved in the enzymatic mechanism. The cAMP produced by AC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Reading Frames
In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames will be "open" (the "reading", however, refers to the RNA produced by transcription of the DNA and its subsequent interaction with the ribosome in translation). Such an ORF may contain a start codon (usually AUG in terms of RNA) and by definition cannot extend beyond a stop codon (usually UAA, UAG or UGA in RNA). That start codon (not necessarily the first) indicates where translation may start. The transcription termination site is located after the ORF, beyond the translation stop codon. If transcription were to cease before the stop codon, an incomplete protein would be made during translation. In eukaryotic genes with multiple exons, introns are removed and exons are then joined together after transcription to yield the final ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
