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NrsZ Small RNA
NrsZ (nitrogen regulated small RNA) is a bacterial small RNA found in the opportunistic pathogen ''Pseudomonas aeruginosa'' PAO1. Its transcription is induced during nitrogen limitation by the NtrB/C two-component system (an important regulator of nitrogen assimilation and swarming motility) together with the alternative sigma factor RpoN ( a global regulator involved in nitrogen metabolism). NrsZ by activating ''rhlA (''a gene essential for rhamnolipids synthesis) positively regulates the production of rhamnolipid surfactants needed for swarming motility. See also * ''Pseudomonas'' sRNA * SrbA sRNA SrbA ( sRNA regulator of biofilms A) is a small regulatory non-coding RNA identified in pathogenic ''Pseudomonas aeruginosa'.'' It is important for biofilm formation and pathogenicity. Bacterial strain with deleted SrbA had reduced biofilm mass. A ... * AsponA antisense RNA References Non-coding RNA {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Structure
Protein secondary structure is the three dimensional form of ''local segments'' of proteins. The two most common secondary structural elements are alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary structure elements typically spontaneously form as an intermediate before the protein folds into its three dimensional tertiary structure. Secondary structure is formally defined by the pattern of hydrogen bonds between the amino hydrogen and carboxyl oxygen atoms in the peptide backbone. Secondary structure may alternatively be defined based on the regular pattern of backbone dihedral angles in a particular region of the Ramachandran plot regardless of whether it has the correct hydrogen bonds. The concept of secondary structure was first introduced by Kaj Ulrik Linderstrøm-Lang at Stanford in 1952. Other types of biopolymers such as nucleic acids also possess characteristic secondary structures. Types The most common secondary st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Conservation
In evolutionary biology, conserved sequences are identical or similar Sequence (biology), sequences in nucleic acids (DNA sequence, DNA and RNA) or peptide sequence, proteins across species (homology (biology)#Orthology, orthologous sequences), or within a genome (homology (biology)#Paralogy, paralogous sequences), or between donor and receptor taxa (Sequence homology#Xenology, xenologous sequences). Conservation indicates that a sequence has been maintained by natural selection. A highly conserved sequence is one that has remained relatively unchanged far back up the phylogenetic tree, and hence far back in geological time. Examples of highly conserved sequences include the Ribosomal RNA, RNA components of ribosomes present in all domain (biology), domains of life, the homeobox sequences widespread amongst Eukaryotes, and the tmRNA in Bacteria. The study of sequence conservation overlaps with the fields of genomics, proteomics, evolutionary biology, phylogenetics, bioinformatics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic re ... [...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 abbreviatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas Aeruginosa
''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic– facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aeruginosa'' is a multidrug resistant pathogen recognized for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses – hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes. The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions – most notably cystic fibrosis and traumatic burns. It generally affects the immunocompromised but can also infect the immunocompetent as in hot tub folliculitis. Treatment of ''P. aeruginosa'' infections can be difficult due to its natural resistance to antibiotics. When more advanced antibiotic drug regimens are needed adverse eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Assimilation
Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N2) depend on the ability to assimilate nitrate or ammonia for their needs. Other organisms, like animals, depend entirely on organic nitrogen from their food. Nitrogen assimilation in plants Plants absorb nitrogen from the soil in the form of nitrate (NO3−) and ammonium (NH4+). In aerobic soils where nitrification can occur, nitrate is usually the predominant form of available nitrogen that is absorbed. However this is not always the case as ammonia can predominate in grasslands and in flooded, anaerobic soils like rice paddies. Plant roots themselves can affect the abundance of various forms of nitrogen by changing the pH and secreting organic compounds or oxygen. This influences microbial activities like the inter-conversion of various nitrogen species, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swarming Motility
Swarming motility is a rapid (2–10 μm/s) and coordinated translocation of a bacterial population across solid or semi-solid surfaces, and is an example of bacterial multicellularity and swarm behaviour. Swarming motility was first reported by Jorgen Henrichsen and has been mostly studied in genus '' Serratia'', ''Salmonella'', ''Aeromonas ''Aeromonas'' is a genus of Gram-negative, facultative anaerobic, rod-shaped bacteria that morphologically resemble members of the family Enterobacteriaceae. Most of the 14 described species have been associated with human diseases. The most imp ...'', '' Bacillus'', '' Yersinia'', '' Pseudomonas'', '' Proteus'', '' Vibrio'' and '' Escherichia''. This multicellular behavior has been mostly observed in controlled laboratory conditions and relies on two critical elements: 1) the nutrient composition and 2) viscosity of culture medium (i.e. % agar). One particular feature of this type of motility is the formation of dendritic fractal-like pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma Factor
A sigma factor (σ factor or specificity factor) is a protein needed for initiation of transcription in bacteria. It is a bacterial transcription initiation factor that enables specific binding of RNA polymerase (RNAP) to gene promoters. It is homologous to archaeal transcription factor B and to eukaryotic factor TFIIB. The specific sigma factor used to initiate transcription of a given gene will vary, depending on the gene and on the environmental signals needed to initiate transcription of that gene. Selection of promoters by RNA polymerase is dependent on the sigma factor that associates with it. They are also found in plant chloroplasts as a part of the bacteria-like plastid-encoded polymerase (PEP). The sigma factor, together with RNA polymerase, is known as the RNA polymerase holoenzyme. Every molecule of RNA polymerase holoenzyme contains exactly one sigma factor subunit, which in the model bacterium ''Escherichia coli'' is one of those listed below. The number of sigma f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamnolipid
Rhamnolipids are a class of glycolipid produced by ''Pseudomonas aeruginosa'', amongst other organisms, frequently cited as bacterial surfactants. They have a glycosyl head group, in this case a rhamnose moiety, and a 3-(hydroxyalkanoyloxy)alkanoic acid (HAA) fatty acid tail, such as 3-hydroxydecanoic acid. Specifically there are two main classes of rhamnolipids: mono-rhamnolipids and di-rhamnolipids, which consist of one or two rhamnose groups respectively. Rhamnolipids are also heterogeneous in the length and degree of branching of the HAA moiety, which varies with the growth media used and the environmental conditions. Rhamnolipids biosynthesis The first genes discovered in a mutagenesis screen for mutants unable to produce rhamnolipids were ''rhlA'' and ''rhlB''. They are arranged in an operon, adjacent to ''rhlRI'', a master regulator of quorum sensing in ''Pseudomonas aeruginosa''. The proteins encoded by ''rhlA'' and ''rhlB''; RhlA and RhlB respectively, are expected to fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas SRNA
''Pseudomonas'' sRNA are non-coding RNAs (ncRNA) that were predicted by the bioinformatic program SRNApredict2. This program identifies putative sRNAs by searching for co-localization of genetic features commonly associated with sRNA-encoding genes and the expression of the predicted sRNAs was subsequently confirmed by Northern blot analysis. These sRNAs have been shown to be conserved across several ''pseudomonas'' species but their function is yet to be determined. Using Tet-Trap genetic approach RNAT genes post-transcriptionally regulated by temperature upshift were identified: ''ptxS'' (implicated in virulence) and PA5194. See also * ''Bacillus subtilis'' sRNA * ''Caenorhabditis elegans'' sRNA * ''Mycobacterium tuberculosis'' sRNA * ''Bacteroides thetaiotaomicron'' sRNA *NrsZ small RNA * AsponA antisense RNA *Repression of heat shock gene expression (ROSE) element *SrbA sRNA SrbA ( sRNA regulator of biofilms A) is a small regulatory non-coding RNA identified in pathogenic '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SrbA SRNA
SrbA ( sRNA regulator of biofilms A) is a small regulatory non-coding RNA identified in pathogenic ''Pseudomonas aeruginosa'.'' It is important for biofilm formation and pathogenicity. Bacterial strain with deleted SrbA had reduced biofilm mass. As the ability to form biofilms can contribute to the ability a pathogen to thrive within the host, the ''C. elegans ''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' ( ...'' hosts infected with the srbA deleted strain displayed significantly lower mortality rate than the wild-type strain. However, the deletion of srbA had no effect on growth or antibiotic resistance in ''P. aeruginosa''. See also * NrsZ small RNA * ''Pseudomonas'' sRNA * AsponA antisense RNA References Non-coding RNA {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AsponA Antisense RNA
AsponA is a small asRNA transcribed antisense to the penicillin-binding protein 1A gene called ''ponA.'' It was identified by RNAseq and the expression was validated by 5' and 3' RACE experiments in '' Pseudomanas aeruginosa''. ''AsponA'' expression was up or down regulated under different antibiotic stress. Owing to its location it may be able to prevent the transcription or translation of the opposite gene. Study by Wurtzel ''et al.'' and Ferrara ''et al.'' also detected its expression. See also * NrsZ small RNA * SrbA sRNA SrbA ( sRNA regulator of biofilms A) is a small regulatory non-coding RNA identified in pathogenic ''Pseudomonas aeruginosa'.'' It is important for biofilm formation and pathogenicity. Bacterial strain with deleted SrbA had reduced biofilm mass. A ... * ''Pseudomonas'' sRNA References {{Reflist Non-coding RNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
