|
Tombusvirus 5′ UTR
Tombusvirus 5′ UTR is an important cis-regulatory region of the Tombus virus genome. Tomato bushy stunt virus is the prototype member of the Tombusviridae family. The genome of this virus is positive sense single stranded RNA. Replication occurs via a negative strand RNA intermediate. In addition to viral proteins p33 and the RNA-dependent RNA polymerase p92, and unknown host factors, conserved and structural regions within the 5′ untranslated region (5′ UTR) are important for regulating genome replication. 2 RNA domains in the 5′ UTR have been reported, a 5′ T-shaped domain (TSD) followed by a stem-loop (SL5) and a downstream domain (DSD). TSD-DSD interactions are proposed to be involved in the mediation of viral RNA replication. An interesting feature of Tombusvirus is its ability to support the replication of defective interfering (DI) RNAs. These sub-viral replicons are small, non-coding, deletion mutants of the viral genome that maintain cis-acting RNA elements ... [...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] |
Cis-regulatory Element
''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] |
Virus
A virus is a wikt:submicroscopic, submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tombusvirus
''Tombusvirus'' is a genus of viruses, in the family ''Tombusviridae''. Plants serve as natural hosts. There are 17 species in this genus. Symptoms associated with this genus include mosaic. The name of the genus comes from ''Tomato bushy stunt virus''. Taxonomy The genus contains the following species: * '' Artichoke mottled crinkle virus'' * '' Carnation Italian ringspot virus'' * '' Cucumber Bulgarian virus'' * ''Cucumber necrosis virus'' * ''Cymbidium ringspot virus'' * ''Eggplant mottled crinkle virus'' * ''Grapevine Algerian latent virus'' * ''Havel River virus'' * '' Lato River virus'' * ''Limonium flower distortion virus'' * ''Moroccan pepper virus'' * ''Neckar River virus'' * '' Pelargonium leaf curl virus'' * '' Pelargonium necrotic spot virus'' * '' Petunia asteroid mosaic virus'' * '' Sikte waterborne virus'' * ''Tomato bushy stunt virus'' Structure Viruses in ''Tombusvirus'' are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. The diameter ... [...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] |
Positive-sense RNA
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context, sense may have slightly different meanings. For example, negative-sense strand of DNA is equivalent to the template strand, whereas the positive-sense strand is the non-template strand whose nucleotide sequence is equivalent to the sequence of the mRNA transcript. DNA sense Because of the complementary nature of base-pairing between nucleic acid polymers, a double-stranded DNA molecule will be composed of two strands with sequences that are reverse complements of each other. To help molecular biologists specifically identify each strand individually, the two strands are usually differentiated as the "sense" strand and the "antisense" strand. An individual strand of DNA is referred to as positive-sense (also positive (+) or simply sense) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Five Prime Untranslated Region
The 5′ untranslated region (also known as 5′ UTR, leader sequence, transcript leader, or leader RNA) is the region of a messenger RNA (mRNA) that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript by differing mechanisms in viruses, prokaryotes and eukaryotes. While called untranslated, the 5′ UTR or a portion of it is sometimes translated into a protein product. This product can then regulate the translation of the main coding sequence of the mRNA. In many organisms, however, the 5′ UTR is completely untranslated, instead forming a complex secondary structure to regulate translation. The 5′ UTR has been found to interact with proteins relating to metabolism, and within the 5′ UTR. In addition, this region has been involved in transcription regulation, such as the sex-lethal gene in ''Drosophila''. Regulatory elements within 5′ UTRs have also been linked to mRNA export. General structure ... [...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] |
Tombusvirus 3′ UTR Region IV
Tombusvirus 3′ UTR is an important Cis-regulatory element, cis-regulatory region of the Tombusvirus, Tombus virus genome. Tomato bushy stunt virus is the prototype member of the family Tombusviridae. The genome of this virus is Positive-sense RNA, positive sense single stranded RNA. Replication occurs via a negative strand RNA intermediate. In addition to viral proteins p33 and the RNA-dependent RNA polymerase p92, and unknown host factors, conserved and structural regions within the 3′ UTR, 3′ untranslated region (3′ UTR) are important for regulating genome replication. This 3′ structural element contains a pseudoknot. Other non-coding RNA structures in Tombusvirus include the Tombusvirus 5′ UTR, 5′ UTR and an Tombusvirus internal replication element (IRE), internal replication element. References External links * Cis-regulatory RNA elements Tombusviridae {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
