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Red Clover Necrotic Mosaic Virus Translation Enhancer Elements
Red clover necrotic mosaic virus (RCNMV) contains several structural elements present within the 3′ and 5′ untranslated regions (UTR) of the genome that enhance translation. In eukaryotes transcription is a prerequisite for translation. During transcription the pre-mRNA transcript is processes where a 5′ cap is attached onto mRNA and this 5′ cap allows for ribosome assembly onto the mRNA as it acts as a binding site for the eukaryotic initiation factor eIF4F. Once eIF4F is bound to the mRNA this protein complex interacts with the poly(A) binding protein which is present within the 3′ UTR and results in mRNA circularization. This multiprotein-mRNA complex then recruits the ribosome subunits and scans the mRNA until it reaches the start codon. Transcription of viral genomes differs from eukaryotes as viral genomes produce mRNA transcripts that lack a 5’ cap site. Despite lacking a cap site viral genes contain a structural element within the 5’ UTR known as an internal ... [...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] |
Tombusviridae
''Tombusviridae'' is a family of single-stranded positive sense RNA plant viruses. There are three subfamilies, 17 genera, and 95 species in this family. The name is derived from ''Tomato bushy stunt virus'' (TBSV). Genome All viruses in the family have a non-segmented (monopartite) linear genome, with the exception of Dianthoviruses, whose genome is bipartite. The genome is approximately 4.6–4.8kb in length, lacks a 5' cap and a poly(A) tail, and it encodes 4–6 ORFs. The polymerase encodes an amber stop codon which is the site of a readthrough event within ORF1, producing two products necessary for replication. There is no helicase encoded by the virus. ICTVFamily - Tombusviridae in: Virus Taxonomy. Ninth Report of the International Committee on Taxonomy of Viruses 2012, pp 1111-1138, 23 November 2011, doi:10.1016/B978-0-12-384684-6.00096-3 Structure The RNA is encapsulated in an icosahedral (T=3) capsid, composed of 180 units of a single coat protein 27–42K in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaic Virus
A mosaic virus is any virus that causes infected plant foliage to have a mottled appearance. Such viruses come from a variety of unrelated lineages and consequently there is no taxon that unites all mosaic viruses. All the symptoms of each virus or complex appear the same, so the only way to know exactly which viral subtype is infecting a plant is to send it to a local extension service. Alternatively, commercial testing kits exist for settings like greenhouses. Examples Virus species that contain the word 'mosaic' in their English language common name, as of March 2019, are listed below. However, not all viruses that may cause a mottled appearance belong to species that include the word "mosaic" in the name. See also * Mosaic A mosaic is a pattern or image made of small regular or irregular pieces of colored stone, glass or ceramic, held in place by plaster/mortar, and covering a surface. Mosaics are often used as floor and wall decoration, and were particularly pop . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Untranslated Region
In molecular genetics, an untranslated region (or UTR) refers to either of two sections, one on each side of a coding sequence on a strand of mRNA. If it is found on the 5' side, it is called the 5' UTR (or leader sequence), or if it is found on the 3' side, it is called the 3' UTR (or trailer sequence). mRNA is RNA that carries information from DNA to the ribosome, the site of protein synthesis (translation) within a cell. The mRNA is initially transcribed from the corresponding DNA sequence and then translated into protein. However, several regions of the mRNA are usually not translated into protein, including the 5' and 3' UTRs. Although they are called untranslated regions, and do not form the protein-coding region of the gene, uORFs located within the 5' UTR can be translated into peptides. The 5' UTR is upstream from the coding sequence. Within the 5' UTR is a sequence that is recognized by the ribosome which allows the ribosome to bind and initiate translation. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translation (biology)
In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription (biology), transcription of DNA to RNA in the cell's nucleus (cell), nucleus. The entire process is called gene expression. In translation, mRNA, messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. The polypeptide later protein folding, folds into an Activation energy, active protein and performs its functions in the Cell (biology), cell. The ribosome facilitates decoding by inducing the binding of Base pair, complementary tRNA anticodon sequences to mRNA codons. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA passes through and is "read" by the ribosome. Translation proceeds in three phases: # Initiation: The ribosome assembles around the target mRNA. The first tRNA is attached a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5′ Cap
In molecular biology, the five-prime cap (5′ cap) is a specially altered nucleotide on the 5′ end of some primary transcripts such as precursor messenger RNA. This process, known as mRNA capping, is highly regulated and vital in the creation of stable and mature messenger RNA able to undergo translation during protein synthesis. Mitochondrial mRNA and chloroplastic mRNA are not capped. Structure In eukaryotes, the 5′ cap (cap-0), found on the 5′ end of an mRNA molecule, consists of a guanine nucleotide connected to mRNA via an unusual 5′ to 5′ triphosphate linkage. This guanosine is methylated on the 7 position directly after capping ''in vivo'' by a methyltransferase. It is referred to as a 7-methylguanylate cap, abbreviated m7G. In multicellular eukaryotes and some viruses, further modifications exist, including the methylation of the 2′ hydroxy-groups of the first 2 ribose sugars of the 5′ end of the mRNA. cap-1 has a methylated 2′-hydroxy group ... [...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] |
Eukaryotic Initiation Factor
Eukaryotic initiation factors (eIFs) are Protein, proteins or Protein complex, protein complexes involved in the initiation phase of eukaryotic translation. These proteins help stabilize the formation of ribosomal preinitiation complexes around the start codon and are an important input for Post-transcriptional regulation, post-transcription gene regulation. Several initiation factors form a complex with the small 40S ribosomal subunit and Met-tRNAiMet called the 43S preinitiation complex (43S PIC). Additional factors of the eIF4F complex (eIF4A, E, and G) recruit the 43S PIC to the five-prime cap structure of the mRNA, from which the 43S particle scans 5'-->3' along the mRNA to reach an AUG start codon. Recognition of the start codon by the Met-tRNAiMet promotes gated phosphate and eIF1 release to form the 48S preinitiation complex (48S PIC), followed by large 60S ribosomal subunit recruitment to form the Eukaryotic ribosome (80S), 80S ribosome. There exist many more eukaryotic ini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Ribosome Entry Site
An internal ribosome entry site, abbreviated IRES, is an RNA element that allows for translation initiation in a cap-independent manner, as part of the greater process of protein synthesis. In eukaryotic translation, initiation typically occurs at the 5' end of mRNA molecules, since 5' cap recognition is required for the assembly of the initiation complex. The location for IRES elements is often in the 5'UTR, but can also occur elsewhere in mRNAs. History IRES sequences were first discovered in 1988 in the poliovirus (PV) and encephalomyocarditis virus (EMCV) RNA genomes in the labs of Nahum Sonenberg and Eckard Wimmer, respectively. They are described as distinct regions of RNA molecules that are able to recruit the eukaryotic ribosome to the mRNA. This process is also known as cap-independent translation. It has been shown that IRES elements have a distinct secondary or even tertiary structure, but similar structural features at the levels of either primary or secondary structur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritance. This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA. The cell possesses the distinctive property of division, which makes replication of DNA essential. DNA is made up of a double helix of two complementary strands. The double helix describes the appearance of a double-stranded DNA which is thus composed of two linear strands that run opposite to each other and twist together to form. During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, a process referred to as semiconservative replication. As a result of semi-conservative rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cap-independent Translation Element
In molecular biology, a cap-independent translation element (CITE or 3'CITE) is an RNA sequence found in the 3'UTR of many RNA plant viruses. Eukaryotic mRNAs contain a 5' cap structure which is required for efficient binding of translation initiation factors. Many viral mRNAs lack the 5' cap, animal virus mRNAs often contain an internal ribosome entry site which functions in translation initiation. Many plant viral mRNAs contain a cap-independent translation element. These elements mediate initiation of translation of the proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ... encoded in the mRNA by either recruiting translation initiation factors or the 60S ribosomal subunit to the viral RNA. In RNA2 of Red clover necrotic mosaic virus (RCNMV) the cap-independent translation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
