do sigma factors bind to dna?
604449
Introduction. Sigma factors are subunits of all bacterial RNA polymerases that are responsible for determining the specificity of promoter DNA binding and efficient initiation of RNA synthesis (transcription).
1347503
Prokaryotic cells (bacteria) contain their chromosome as circular DNA. Usually the entire genome is a single circle, but often there are extra circles called plasmids. The DNA is packaged by DNA-binding proteins.
1351133
Cytosine and thymine are pyrimidines which are structures composed of a single six-sided ring. Adenine always binds to thymine, while cytosine and guanine always bind to one another. This relationship is called complementary base paring.
1376843
Activators (and sometimes inducers) instigate positive regulation, and repressors instigate negative regulation. When an activator or inducer binds to an operon, the transcription process either increases in rate or is allowed to continue.
191341
Gene expression in eukaryotic cells is regulated by repressors as well as by transcriptional activators. Like their prokaryotic counterparts, eukaryotic repressors bind to specific DNA sequences and inhibit transcription. ... Other repressors compete with activators for binding to specific regulatory sequences.
18806
function. Basal, or general, transcription factors are necessary for RNA polymerase to function at a site of transcription in eukaryotes. They are considered the most basic set of proteins needed to activate gene transcription, and they include a number of proteins, such as TFIIA (transcription factor…
1177056
The stability of the DNA double helix depends on a fine balance of interactions including hydrogen bonds between bases, hydrogen bonds between bases and surrounding water molecules, and base-stacking interactions between adjacent bases.
1374216
Chromosome Structure. Prokaryotic cells (bacteria) contain their chromosome as circular DNA. Usually the entire genome is a single circle, but often there are extra circles called plasmids. The DNA is packaged by DNA-binding proteins.
720415
In bacteria, DNA methylation is used as a signal for the regulation of a specific DNA-protein interaction. Methylation systems typically comprise of a DNA methylase and one or more DNA binding proteins that can overlap the target methylation site on DNA, subsequently blocking methylation of that site.
951361
When DNA is compacted by histones into 10-nm and 30-nm fibers, the DNA is unable to interact with proteins required for gene expression. Therefore, to allow for these proteins to act, the chromatin must constantly alter its structure.
1029251
There are thousands of proteins in our cells that help modulate DNA's functions. These proteins are called DNA-binding proteins, because they attach to DNA. DNA binding proteins do many jobs including controlling protein production, regulating cell growth and division, and storing DNA inside the nucleus.
19064
Generally, molecules are called sigma complexes to stress the difference between them and pi complexes which can also be created from cyclic annulenes. First ones are bonded using sigma bonds, the other ones use pre-existing pi orbitals.
1372415
Sigma (σ) factor is the peoptide subunit needed for the initiation of RNA transcription in prokaryotic organisms as seen here. As opposed to eukaryotes, who utilize a variety of proteins to initiate gene transcription, prokaryotic transcription is initiated almost completely by a σ-factor.
267973
Describe the types of chemical bonds and forces of the DNA double helix. The DNA double helix has two types of bonds, covalent and hydrogen. Covalent bonds exist within each linear strand and strongly bond bases, sugars, and phosphate groups (both within each component and between components).
196432
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.
1184072
Translation components include mRNA, small and large ribosomal subunits, initiation factors, elongation factors and tRNA. In transcription, a DNA double helix is denatured to allow the enzyme to access the template strand. In translation, no such denaturing is necessary, as the template is a single mRNA strand.
1229488
Prokaryotes only carry three promoter elements, -10, -35, and the UP elements, whereas eukaryotes carry a wide variety of promoter elements (4). In addition, the use of enhancers in eukaryotic transcription allows the promoter sites in remote location on the DNA to initiate transcription.