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CspA MRNA 5′ UTR
cspA mRNA 5' UTR is the untranslated region of th''cspA'' gene which is important in the cold shock response in Enterobacteriales such as ''E. coli''. The 5' UTR element acts as an RNA thermometer, regulating the expression of ''cspA'' in response to temperature. By regulating temperature, cspA proteins carry out the vital function of homeostasis. The 5' UTR was first suspected to be significant when mutations within this region of ''cspA'' significantly increased the stability of the transcript at 37°C. The secondary structure of cspA mRNA changes in response to temperature; at 37 °C the transcript is unstable and less efficiently translated than at lower temperatures. Unlike other RNA thermometers (such as FourU), the secondary structure is not reliant on the melting of a hairpin in order to affect gene expression. Instead, in temperatures below 20 °C a cis-regulatory region of ncRNA in the 5' UTR of ''cspA'' presents the Shine-Dalgarno sequence and AUG s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis-reg
''Cis''-regulatory elements (CREs) or ''Cis''-regulatory modules (CRMs) are regions of non-coding DNA which gene regulation, regulate the transcription (genetics), transcription of neighboring genes. CREs are vital components of genetic regulatory networks, which in turn control morphogenesis, the development of anatomy, and other aspects of embryogenesis, embryonic development, studied in evolutionary developmental biology. CREs are found in the vicinity of the genes that they regulate. CREs typically regulate gene transcription by binding to transcription factors. A single transcription factor may bind to many CREs, and hence control the expression of many genes (pleiotropy). The Latin prefix ''cis'' means "on this side", i.e. on the same molecule of DNA as the gene(s) to be transcribed. CRMs are stretches of DNA, usually 100–1000 DNA base pairs in length, where a number of transcription factors can bind and regulation of gene expression, regulate expression of nearby genes an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stem-loop
Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions, base-pair to form a double helix that ends in an unpaired loop. The resulting structure is a key building block of many RNA secondary structures. As an important secondary structure of RNA, it can direct RNA folding, protect structural stability for messenger RNA (mRNA), provide recognition sites for RNA binding proteins, and serve as a substrate for enzymatic reactions. Formation and stability The formation of a stem-loop structure is dependent on the stability of the resulting helix and loop regions. The first prerequisite is the presence of a sequence that can fold back on itself to form a paired double helix. The stability of this helix is determined by its length, the number of mismatches or bulges it co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ROSE Element
The repression of heat shock gene expression (ROSE) element is an RNA element found in the 5' UTR of some heat shock protein's mRNAs. The ROSE element is an RNA thermometer that negatively regulates heat shock gene expression. The secondary structure is thought to be altered by temperature, thus it is an RNA thermometer. This structure blocks access to the ribosome binding site at normal temperatures. During heat shock however, the structure changes freeing the ribosome binding site and allowing expression to occur. A partial structure of this RNA element has been determined using NMR. ROSE1 and ROSEAT2 ROSE1 and ROSEAT2 are specific examples of ROSE elements. ROSE1 is found in '' Bradyrhizobium japonicum'' whereas ROSEAT2 is a closely related element from ''Agrobacterium tumefaciens''. The two RNA elements have similar secondary structures with ROSE1 having an extra hairpin. All ROSE elements contain a characteristic 'bulged G' opposite the Shine-Dalgarno sequence binding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hfq Binding SRNA
An Hfq binding sRNA is an sRNA that binds the bacterial RNA binding protein called Hfq. A number of bacterial small RNAs which have been shown to bind to Hfq have been characterised (see list). Many of these RNAs share a similar structure composed of three stem-loops. Several studies have expanded this list, and experimentally validated a total of 64 Hfq binding sRNA in ''Salmonella Typhimurium''. A transcriptome wide study on Hfq binding sites in ''Salmonella'' mapped 126 Hfq binding sites within sRNAs. Genomic SELEX has been used to show that Hfq binding RNAs are enriched in the sequence motif 5′-AAYAAYAA-3′. Genome-wide study identified 40 candidate Hfq-dependent sRNAs in plant pathogen ''Erwinia amylovora.'' 12 of them were confirmed by Northern blot. Bacterial Hfq binding sRNAs * DicF RNA * DsrA RNA * FnrS RNA * GadY RNA * GcvB RNA * IsrJ RNA * MicA RNA / SraD RNA * MicC RNA * MicF RNA * OmrA RNA / OmrB RNA / RygA RNA / RygB RNA / SraE RNA * OxyS RNA * Qrr RN ... [...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] |
Proteome
The proteome is the entire set of proteins that is, or can be, expressed by a genome, cell, tissue, or organism at a certain time. It is the set of expressed proteins in a given type of cell or organism, at a given time, under defined conditions. Proteomics is the study of the proteome. Types of proteomes While proteome generally refers to the proteome of an organism, multicellular organisms may have very different proteomes in different cells, hence it is important to distinguish proteomes in cells and organisms. A cellular proteome is the collection of proteins found in a particular cell type under a particular set of environmental conditions such as exposure to hormone stimulation. It can also be useful to consider an organism's complete proteome, which can be conceptualized as the complete set of proteins from all of the various cellular proteomes. This is very roughly the protein equivalent of the genome. The term ''proteome'' has also been used to refer to the collectio ... [...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-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Start Codon
The start codon is the first codon of a messenger RNA (mRNA) transcript translated by a ribosome. The start codon always codes for methionine in eukaryotes and Archaea and a N-formylmethionine (fMet) in bacteria, mitochondria and plastids. The most common start codon is AUG (i.e., ATG in the corresponding DNA sequence). The start codon is often preceded by a 5' untranslated region ( 5' UTR). In prokaryotes this includes the ribosome binding site. Alternative start codons Alternative start codons are different from the standard AUG codon and are found in both prokaryotes (bacteria and archaea) and eukaryotes. Alternate start codons are still translated as Met when they are at the start of a protein (even if the codon encodes a different amino acid otherwise). This is because a separate transfer RNA (tRNA) is used for initiation. Eukaryotes Alternate start codons (non-AUG) are very rare in eukaryotic genomes. However, naturally occurring non-AUG start codons have been rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis-regulatory
''Cis''-regulatory elements (CREs) or ''Cis''-regulatory modules (CRMs) are regions of non-coding DNA which regulate the transcription of neighboring genes. CREs are vital components of genetic regulatory networks, which in turn control morphogenesis, the development of anatomy, and other aspects of embryonic development, studied in evolutionary developmental biology. CREs are found in the vicinity of the genes that they regulate. CREs typically regulate gene transcription by binding to transcription factors. A single transcription factor may bind to many CREs, and hence control the expression of many genes (pleiotropy). The Latin prefix ''cis'' means "on this side", i.e. on the same molecule of DNA as the gene(s) to be transcribed. CRMs are stretches of DNA, usually 100–1000 DNA base pairs in length, where a number of transcription factors can bind and regulate expression of nearby genes and regulate their transcription rates. They are labeled as ''cis'' because they are ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FourU Thermometer
__NOTOC__ FourU thermometers are a class of non-coding RNA thermometers found in ''Salmonella''. They are named 'FourU' due to the four highly conserved uridine nucleotides found directly opposite the Shine-Dalgarno sequence on hairpin II (''pictured''). RNA thermometers such as FourU control regulation of temperature via heat shock proteins in many prokaryotes. FourU thermometers are relatively small RNA molecules, only 57 nucleotides in length, and have a simple two-hairpin structure. FourU are found in the 5' untranslated region of the gene for heat shock protein ''Salmonella agsA'', they repress translation of this protein by base-pairing the Shine-Dalgarno sequence of the gene's mRNA. This prevents ribosomes from binding the start codon of the gene. They are also found in the 5'UTR of ''htrA'' (high temperature requirement) genes in ''Salmonella'' and ''E.coli.'' In ''V. cholerae'' fourU thermometer in the 5' of ''toxT'' controls its temperature-dependent translation. At hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterobacteriales
Enterobacterales is an order of Gram-negative bacteria, Gram-negative, non-spore forming, Facultative anaerobic organism, facultatively anaerobic, rod-shaped bacteria with the class Gammaproteobacteria. The type genus of this order is ''Enterobacter.'' The name Enterobacterales is derived from the Latin term ''Enterobacter'', referring the type genus of the order and the suffix "-ales", an ending used to denote an order. Together, Enterobacterales refers to an order whose nomenclatural type is the genus ''Enterobacter''. Historical Identification and Systematics Enterobacterales was proposed in 2005 under the name "Enterobacteriales". However, the name "Enterobacteriales" was not validated according to the rules of the ''International Code of Nomenclature of Prokaryotes,'' thus it lacked standing in nomenclature, so the name was written in parentheses. "Enterobacteriales" was a monotypic order, containing only the family ''Enterobacteriaceae'', and shared its type genus ''Esch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
