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SprX Small RNA
In molecular biology the small pathogenicity island RNA X (alias RsaOR) gene is a bacterial non-coding RNA. It was discovered in a large-scale analysis of ''Staphylococcus aureus''. SprX was shown to influence antibiotic resistance of the bacteria to Vancomycin and Teicoplanin glycopeptides, which are used to treat MRSA infections. In this study the authors identified a SprX target, stage V sporulation protein G (Spo VG). By reducing Spo VG expression levels, SprX affects ''S. aureus'' resistance to the glycopeptide antibiotics. Further work demonstrated its involvement in the regulation of pathogenicity factors. See also * SprD __NOTOC__ In molecular biology SprD (Small pathogenicity island RNA D) is a non-coding RNA expressed on pathogenicity islands in ''Staphylococcus aureus''. It was identified ''in silico'' along with a number of other sRNAs (SprA-G) through microar ... 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] |
Non-coding RNA
A non-coding RNA (ncRNA) is a functional RNA molecule that is not 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 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, exRNAs, scaRNAs and the long ncRNAs such as Xist and HOTAIR. The number of non-coding RNAs within the human genome is unknown; however, recent transcriptomic and 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 referred to as "junk RNA"), spurious transcriptions. Others, however, disagree, arguing instead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aureu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimicrobial Resistance
Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. Protozoa evolve antiprotozoal resistance, and bacteria evolve antibiotic resistance. Those bacteria that are considered extensively drug resistant (XDR) or totally drug-resistant (TDR) are sometimes called "superbugs".A.-P. Magiorakos, A. Srinivasan, R. B. Carey, Y. Carmeli, M. E. Falagas, C. G. Giske, S. Harbarth, J. F. Hinndler ''et al''Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria... Clinical Microbiology and Infection, Vol 8, Iss. 3 first published 27 July 2011 ia Wiley Online Library Retrieved 28 August 2020 Although antimicrobial resistance is a naturally-occurring process, it is often the result of improper usage of the drugs and management of the infections. Antibiotic resistance is a major sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vancomycin
Vancomycin is a glycopeptide antibiotic medication used to treat a number of bacterial infections. It is recommended intravenously as a treatment for complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, and meningitis caused by methicillin-resistant ''Staphylococcus aureus''. Blood levels may be measured to determine the correct dose. Vancomycin is also taken by mouth as a treatment for severe ''Clostridium difficile'' colitis. When taken by mouth it is poorly absorbed. Common side effects include pain in the area of injection and allergic reactions. Occasionally, hearing loss, low blood pressure, or bone marrow suppression occur. Safety in pregnancy is not clear, but no evidence of harm has been found, and it is likely safe for use when breastfeeding. It is a type of glycopeptide antibiotic and works by blocking the construction of a cell wall. Vancomycin was approved for medical use in the United States in 1958. It is on the Wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teicoplanin
Teicoplanin is an antibiotic used in the prophylaxis and treatment of serious infections caused by Gram-positive bacteria, including methicillin-resistant ''Staphylococcus aureus'' and '' Enterococcus faecalis''. It is a semisynthetic glycopeptide antibiotic with a spectrum of activity similar to vancomycin. Its mechanism of action is to inhibit bacterial cell wall synthesis. Teicoplanin is marketed by Sanofi-Aventis under the trade name Targocid. Other trade names include Ticocin marketed by Cipla(India). Oral teicoplanin has been demonstrated to be effective in the treatment of pseudomembranous colitis and ''Clostridium difficile''-associated diarrhoea, with comparable efficacy with vancomycin. Its strength is considered to be due to the length of the hydrocarbon chain. Teicoplanin is produced by so-called "rare" actinobacterium ''Actinoplanes teichomyceticus'' ATCC 31121, belonging to the ''Micromonosporaceae'' family. Biosynthetic pathway leading to teicoplanin, as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycopeptide
Glycopeptides are peptides that contain carbohydrate moieties (glycans) covalently attached to the side chains of the amino acid residues that constitute the peptide. Over the past few decades it has been recognised that glycans on cell surface (attached to membrane proteins or lipids) and those bound to proteins (glycoproteins) play a critical role in biology. For example, these constructs have been shown to play important roles in fertilization, the immune system, brain development, the endocrine system, and inflammation. The synthesis of glycopeptides provides biological probes for researchers to elucidate glycan function in nature and products that have useful therapeutic and biotechnological applications. Glycopeptide linkage variety ''N''-Linked glycans ''N''-Linked glycans derive their name from the fact that the glycan is attached to an asparagine (Asn, N) residue, and are amongst the most common linkages found in nature. Although the majority of N-linked glycans tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methicillin-resistant Staphylococcus Aureus
Methicillin-resistant ''Staphylococcus aureus'' (MRSA) is a group of Gram-positive bacteria that are genetically distinct from other strains of ''Staphylococcus aureus''. MRSA is responsible for several difficult-to-treat infections in humans. It caused more than 100,000 deaths attributable to antimicrobial resistance in 2019. MRSA is any strain of ''S. aureus'' that has developed (through natural selection) or acquired (through horizontal gene transfer) a multiple drug resistance to beta-lactam antibiotics. Beta-lactam (β-lactam) antibiotics are a broad-spectrum group that include some penams (penicillin derivatives such as methicillin and oxacillin) and cephems such as the cephalosporins. Strains unable to resist these antibiotics are classified as methicillin-susceptible ''S. aureus'', or MSSA. MRSA is common in hospitals, prisons, and nursing homes, where people with open wounds, invasive devices such as catheters, and weakened immune systems are at greater risk of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SprD
__NOTOC__ In molecular biology SprD (Small pathogenicity island RNA D) is a non-coding RNA expressed on pathogenicity islands in ''Staphylococcus aureus''. It was identified ''in silico'' along with a number of other sRNAs (SprA-G) through microarray analysis which were confirmed using a Northern blot. SprD has been found to significantly contribute to causing disease in an animal model. Function SprD is located between genes ''scn'' and ''chp'' in the innate immune evasion cluster (IEC) of the ''S. aureus'' genome. Its placement within this region was the first indication of a virulence-factor regulatory function. SprD binds with ''sbi'' (''Staphylococcus aureus'' binder of IgG) mRNA which encodes an immune evasion protein. It occludes the Shine-Dalgarno sequence and the initiation codon of ''sbi'', forming a ''sbi'' mRNA-SprD duplex repressing the translation of the mRNA. ''sbi'' protein interferes with the host's innate immune response by binding Factor H, Complement compo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
