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Aggregatibacter Iron-regulated SRNA
Four non-coding small RNAs containing a Fur box-like (ferric uptake regulator) sequence were identified by bioinformatics analysis in ''Aggregatibacter actinomycetemcomitans'' ''HK1651'' called JA01-JA04. The transcription of sRNAs was confirmed by Northern blot. Fur binding was demonstrated to each sRNA promoter, and that transcription of the sRNAs was decreased in presence of iron and increased by iron limitation. JA03 may have the ability to regulate biofilm formation. JA01 is conserved only among ''A. actinomycetemcomitans''. JA02 is present in both ''A. actinomycetemcomitans and P. multocida. J''A 03 and JA04 are most widely conserved and have orthologues across many ''Pasteurellaceae The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notabl ...''. HrrF RNA is another Fur-regulated sRNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small RNA
Small RNA (sRNA) are polymeric RNA molecules that are less than 200 nucleotides in length, and are usually non-coding. RNA silencing is often a function of these molecules, with the most common and well-studied example being RNA interference (RNAi), in which endogenously expressed microRNA (miRNA) or exogenously derived small interfering RNA (siRNA) induces the degradation of complementary messenger RNA. Other classes of small RNA have been identified, including piwi-interacting RNA (piRNA) and its subspecies repeat associated small interfering RNA (rasiRNA). Small RNA "is unable to induce RNAi alone, and to accomplish the task it must form the core of the RNA–protein complex termed the RNA-induced silencing complex (RISC), specifically with Argonaute protein". Small RNA have been detected or sequenced using a range of techniques, including directly by MicroRNA sequencing on several sequencing platforms, or indirectly through genome sequencing and analysis. Identification of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferric Uptake Regulator Family
In molecular biology, the ferric uptake regulator family is a family of bacterial proteins involved in regulating metal ion uptake and in metal homeostasis. The family is named for its founding member, known as the ferric uptake regulator or ferric uptake regulatory protein (Fur). Fur proteins are responsible for controlling the intracellular concentration of iron in many bacteria. Iron is essential for most organisms, but its concentration must be carefully managed over a wide range of environmental conditions; high concentrations can be toxic due to the formation of reactive oxygen species. Function Members of the ferric uptake regulator family are transcription factors that primarily exert their regulatory effects as repressors: when bound to their cognate metal ion, they are capable of binding DNA and preventing expression of the genes they regulate, but under low concentrations of metal, they undergo a conformational change that prevents DNA binding and lifts the repressio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregatibacter Actinomycetemcomitans
''Aggregatibacter actinomycetemcomitans'' is a Gram-negative, facultative anaerobe, nonmotile bacterium that is often found in association with localized aggressive periodontitis, a severe infection of the periodontium. It is also suspected to be involved in chronic periodontitis. Less frequently, ''A. actinomycetemcomitans'' is associated with nonoral infections such as endocarditis. Its role in aggressive periodontitis was first discovered by Danish-born periodontist Jørgen Slots, a professor of dentistry and microbiology at the University of Southern California School of Dentistry. 'Bacterium actinomycetem comitans' was first described by Klinger (1912) as coccobacillary bacteria isolated with ''Actinomyces'' from actinomycotic lesions in humans. It was reclassified as ''Actinobacillus actinomycetemcomitans'' by Topley & Wilson (1929) and as ''Haemophilus actinomycetemcomitans'' by Potts ''et al.'' (1985). The species has attracted attention because of its association with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasteurellaceae
The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notable group of facultative anaerobes. Their biochemical characteristics can be distinguished from the related Enterobacteriaceae by the presence of oxidase, and from most other similar bacteria by the absence of flagella. Bacteria in the family Pasteurellaceae have been classified into a number of genera based on metabolic properties, but these classifications are not generally accurate reflections of the evolutionary relationships between different species. ''Haemophilus influenzae'' was the first organism to have its genome sequenced and has been studied intensively by genetic and molecular methodologies. The genus ''Haemophilus'' is a notorious human pathogen associated with bacteremia, pneumonia, meningitis and chancroid. Other pathogenic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HrrF RNA
HrrF RNA (''Haemophilus'' regulatory RNA responsive to iron Fe) is a small non-coding RNA involved in iron homeostasis in ''Haemophilus'' species. Orthologues exist only among other '' Pasteurellacae.'' Iron- regulated sRNAs JA01- JA04 were identified in related ''Aggregatibacte''r. It is an analog to PrrF and RyhB RNAs. HrrF is maximally expressed when iron levels are low. Ferric uptake regulator (Fur) binds upstream of the ''hrrF'' promoter. HrrF stability is not dependent on the RNA chaperone Hfq. RNA-seq has shown that HrrF targets are mRNAs of genes whose products are involved in molybdate In chemistry a molybdate is a compound containing an oxoanion with molybdenum in its highest oxidation state of 6. Molybdenum can form a very large range of such oxoanions which can be discrete structures or polymeric extended structures, althou ... uptake, deoxyribonucleotide synthesis, and amino acid synthesis. See also * NrrF RNA References Non-coding RNA {{mole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RyhB RNA
RyhB RNA is a 90 nucleotide RNA that down-regulates a set of iron-storage and iron-using proteins when iron is limiting; it is itself negatively regulated by the ferric uptake repressor protein, Fur ( Ferric uptake regulator). Discovery The gene was independently identified in two screens, named RyhB by Wassarman ''et al''. and called SraI by Argaman ''et al''. and was found to be expressed only in stationary phase. Function and regulation RyhB RNA levels are inversely correlated with mRNA levels for the ''sdhCDAB'' operon, encoding succinate dehydrogenase, as well as five other genes previously shown to be positively regulated by Fur by an unknown mechanism. These include two other genes encoding enzymes in the tricarboxylic acid cycle, ''acnA'' and ''fumA'', two ferritin genes, ''ftnA'' and ''bfr'', and a gene for superoxide dismutase, ''sodB''. A number of other genes have been predicted computationally and verified as targets by microarray analysis: ''napF'', ''sodA'', ''cysE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PrrF RNA
The PrrF RNAs are small non-coding RNAs involved in iron homeostasis and are encoded by all ''Pseudomonas'' species. The PrrF RNAs are analogs of the RyhB RNA, which is encoded by enteric bacteria. Expression of the PrrF RNAs is repressed by the ferric uptake regulator (Fur) when cells are grown in iron-replete conditions. Under iron limitation, the PrrF RNAs are expressed and act to negatively regulate several genes encoding iron-containing proteins, including SodB and succinate dehydrogenase. As such, PrrF regulation "spares" iron when this nutrient becomes scarce. PrrF and virulence In ''Pseudomonas aeruginosa'', the PrrF RNAs are required for the production of the Pseudomonas quinolone signal (PQS), a quorum sensing molecule that activates the expression of several virulence genes. The phenomenon is mediated by PrrF repressing the expression of enzymes that degrade anthranilic acid, which is the precursor for PQS synthesis. Due to this regulatory link with PQS, the PrrF RNAs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NrrF RNA
NrrF is a non-coding RNA which is regulated by the Ferric uptake regulator (Fur) protein in bacteria. This non-coding RNA was identified in ''Neisseria meningitidis'' and is involved in iron regulation of the succinate dehydrogenase genes sdhA and sdhC. NrrF acts as an antisense RNA and is complementary to the junction between the second and third genes of the sdh operon (sdhD and sdhA). Secondary structure predictions have indicated that this interaction occurs in a single stranded loop region of the NrrF RNA. Under low iron concentration NrrF is present at a high concentration and forms a duplex with the transcript in Hfq dependent manner. The RNA chaperone Hfq acts to enhance binding of NrrF or stabilizes the NrrF/sdh transcript duplex. Binding of NrrF results in down regulation of the sdhCDAB mRNA transcript results in a Fur-dependent positive regulation of succinate dehydrogenase. Another NrrF RNA target is mRNA ''petABC'', coding for cytochrome ''bc1'' ( an essential compon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
