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TFIIA
Transcription factor TFIIA is a nuclear protein involved in the RNA polymerase II-dependent transcription of DNA. TFIIA is one of several general (basal) transcription factors ( GTFs) that are required for all transcription events that use RNA polymerase II. Other GTFs include TFIID, a complex composed of the TATA binding protein TBP and TBP-associated factors (TAFs), as well as the factors TFIIB, TFIIE, TFIIF, and TFIIH. Together, these factors are responsible for promoter recognition and the formation of a transcription preinitiation complex (PIC) capable of initiating RNA synthesis from a DNA template. Functions TFIIA interacts with the TBP subunit of TFIID and aids in the binding of TBP to TATA-box containing promoter DNA. Interaction of TFIIA with TBP facilitates formation of and stabilizes the preinitiation complex. Interaction of TFIIA with TBP also results in the exclusion of negative (repressive) factors that might otherwise bind to TBP and interfere wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GTF2A1
Transcription initiation factor IIA subunit 1 is a protein that in humans is encoded by the ''GTF2A1'' gene. Interactions GTF2A1 has been shown to interact with TATA binding protein and TBPL1 TATA box-binding protein-like protein 1 is a protein that in humans is encoded by the ''TBPL1'' gene. Function Initiation of transcription by RNA polymerase II requires the activities of more than 70 polypeptides. The protein that coordinates .... See also * Transcription Factor II A Model organisms Model organisms have been used in the study of GTF2A1 function. A conditional knockout mouse line called ''Gtf2a1tm1a(KOMP)Wtsi'' was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping References Further reading * * * * * * * * * * * * * * * * * * * {{Transcription factors T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TATA Binding Protein
The TATA-binding protein (TBP) is a general transcription factor that binds specifically to a DNA sequence called the TATA box. This DNA sequence is found about 30 base pairs upstream of the transcription start site in some eukaryotic gene promoters. TBP gene family TBP is a member of a small gene family of TBP-related factors. The first TBP-related factor (TRF/TRF1) was identified in the fruit fly Drosophila, but appears to be fly or insect-specific. Subsequently TBPL1/TRF2 was found in the genomes of many metazoans, whereas vertebrate genomes encode a third vertebrate family member, TBPL2/TRF3. In specific cell types or on specific promoters TBP can be replaced by one of these TBP-related factors, some of which interact with the TATA box similarly to TBP. Role as transcription factor TBP is a subunit of the eukaryotic general transcription factor TFIID. TFIID is the first protein to bind to DNA during the formation of the transcription preinitiation complex of RNA po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TATA Binding Protein
The TATA-binding protein (TBP) is a general transcription factor that binds specifically to a DNA sequence called the TATA box. This DNA sequence is found about 30 base pairs upstream of the transcription start site in some eukaryotic gene promoters. TBP gene family TBP is a member of a small gene family of TBP-related factors. The first TBP-related factor (TRF/TRF1) was identified in the fruit fly Drosophila, but appears to be fly or insect-specific. Subsequently TBPL1/TRF2 was found in the genomes of many metazoans, whereas vertebrate genomes encode a third vertebrate family member, TBPL2/TRF3. In specific cell types or on specific promoters TBP can be replaced by one of these TBP-related factors, some of which interact with the TATA box similarly to TBP. Role as transcription factor TBP is a subunit of the eukaryotic general transcription factor TFIID. TFIID is the first protein to bind to DNA during the formation of the transcription preinitiation complex of RNA po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Transcription Factor
General transcription factors (GTFs), also known as basal transcriptional factors, are a class of protein transcription factors that bind to specific sites (Promoter (genetics), promoter) on DNA to activate Transcription (genetics), transcription of genetic information from DNA to messenger RNA. GTFs, RNA polymerase, and the Mediator (coactivator), mediator (a multi-protein complex) constitute the basic transcriptional apparatus that first bind to the promoter, then start transcription. GTFs are also intimately involved in the process of gene regulation, and most are required for life. A transcription factor is a protein that binds to specific DNA sequences (Enhancer (genetics), enhancer or promoter), either alone or with other proteins in a complex, to control the rate of transcription of genetic information from DNA to messenger RNA by promoting (serving as an Activator (genetics), activator) or blocking (serving as a repressor) the recruitment of RNA polymerase. As a class of pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TATA Box
In molecular biology, the TATA box (also called the Goldberg–Hogness box) is a sequence of DNA found in the core promoter region of genes in archaea and eukaryotes. The bacterial homolog of the TATA box is called the Pribnow box which has a shorter consensus sequence. The TATA box is considered a non-coding DNA sequence (also known as a cis-regulatory element). It was termed the "TATA box" as it contains a consensus sequence characterized by repeating T and A base pairs. How the term "box" originated is unclear. In the 1980s, while investigating nucleotide sequences in mouse genome loci, the Hogness box sequence was found and "boxed in" at the -31 position. When consensus nucleotides and alternative ones were compared, homologous regions were "boxed" by the researchers. The boxing in of sequences sheds light on the origin of the term "box". The TATA box was first identified in 1978 as a component of eukaryotic promoters. Transcription is initiated at the TATA box in TAT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are expressed in the desired cells at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct cell division, cell growth, and cell death throughout life; cell migration and organization (body plan) during embryonic development; and intermittently in response to signals from outside the cell, such as a hormone. There are up to 1600 TFs in the human genome. Transcription factors are members of the proteome as well as regulome. TFs work alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) the recruitment of RNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Preinitiation Complex
The preinitiation complex (abbreviated PIC) is a complex of approximately 100 proteins that is necessary for the transcription of protein-coding genes in eukaryotes and archaea. The preinitiation complex positions RNA polymerase II at gene transcription start sites, denatures the DNA, and positions the DNA in the RNA polymerase II active site for transcription. The minimal PIC includes RNA polymerase II and six general transcription factors: TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH. Additional regulatory complexes (such as the mediator coactivator and chromatin remodeling complexes) may also be components of the PIC. Assembly A classical view of PIC formation at the promoter involves the following steps: * TATA binding protein (TBP, a subunit of TFIID) binds the promoter, creating a sharp bend in the promoter DNA. ** Animals have some TBP-related factors (TRF; TBPL1/ TBPL2). They can replace TBP in some special contexts. * TBP recruits TFIIA, then TFIIB, to the ... [...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] |
Yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitute 1% of all described fungal species. Yeasts are unicellular organisms that evolved from multicellular ancestors, with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae. Yeast sizes vary greatly, depending on species and environment, typically measuring 3–4 µm in diameter, although some yeasts can grow to 40 µm in size. Most yeasts reproduce asexually by mitosis, and many do so by the asymmetric division process known as budding. With their single-celled growth habit, yeasts can be contrasted with molds, which grow hyphae. Fungal species that can take both forms (depending on temperature or other conditions) are ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). Euka ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conserved Sequence
In evolutionary biology, conserved sequences are identical or similar sequences in nucleic acids ( DNA and RNA) or proteins across species ( orthologous sequences), or within a genome ( paralogous sequences), or between donor and receptor taxa ( 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 RNA components of ribosomes present in all 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 and mathematics. History The discovery of the role of DNA in heredity, and observations by Frederick Sanger of variation between animal insulins in 1949, prompt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is translated from messenger RNA, it is created from N-terminus to C-terminus. The convention for writing peptide sequences is to put the C-terminal end on the right and write the sequence from N- to C-terminus. Chemistry Each amino acid has a carboxyl group and an amine group. Amino acids link to one another to form a chain by a dehydration reaction which joins the amine group of one amino acid to the carboxyl group of the next. Thus polypeptide chains have an end with an unbound carboxyl group, the C-terminus, and an end with an unbound amine group, the N-terminus. Proteins are naturally synthesized starting from the N-terminus and ending at the C-terminus. Function C-terminal retention signals While the N-terminus of a protein often c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
