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What is the sequence of nucleotides on DNa to with ran polymerase will attach to start transcription?
Wiki User
∙ 9y ago
A promoter is a segment of DNA that helps RNA polymerase recognize the start of a gene.
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∙ 12y ago
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What does the first nucleotide attach to because DNA polymerase can only add nucleotides to a pre-existing strand?
An RNA primer.
What are the elements of DNA polymerase?
DNA polymerase III (not DNA polymerase) is an enzyme that works in association with other enzymes during the replication of a DNA molecule. DNA replication begins when the enzyme, known as helicase unwinds a DNA strand. Helicase unwinds a DNA strand, thus, in the process, separating the two DNA templates. The result of the unwinding of the DNA molecule is the formation of a replication bubble. Once a DNA molecule is unwound, it is not stable. The DNA molecule is untwisted, broken and rearranged by an enzyme called topoisomerase in order to create stability at the ends of a replication bubble. In addition, the DNA replication bubble is further stabilized by a group of protein complexes known as single strand binding proteins.Once the DNA molecule is unwound and stabilized, an enzyme called primase assembles an RNA sequence that is complementary to the adjacent DNA template. The purpose of this initial RNA sequence is to provide a point at which DNA polymerase III can start to add nucleotides to the corresponding DNA template. Unlike RNA polymerase, DNA polymerase III requires an RNA sequence, which is known as a primer. DNA polymerase III can attach a nucleotide only to the 3 prime end of an existing nucleotide sequence. Once a primer is assembled by primase, DNA polymerase III begins its work of adding nucleotides to the 3 prime end of the primer.It is important to note that replication proceeds in two directions, since a DNA replication bubble consists of two DNA templates. Since DNA polymerase III proceeds in the three prime to 5 prime direction at one DNA template, it also has to proceed in the 3 prime to 5 prime direction on the other DNA template. Since the template run in opposite directions, the second template will consist of multiple primers and thus short segments of DNA. These short segments of DNA are known as Okazaki fragments. The Okazaki fragments are created by DNA polymerase three since it is only able to proceed in the 3 prime to 5 prime direction.After DNA polymerase III completes its work, DNA polymerase I begins to replace the RNA nucleotides of the primers with DNA nucleotides. Once DNA polymerase I replaces the RNA nucleotides with DNA nucleotides, DNA ligase joins the Okazaki fragments together and the result is a new DNA template.
Why do dideoxy nucleotides cause the DNA strand to stop elongating?
It doesn't contain an OHO bond so no other nucleotides can attach to it.
Where does Helicase attach to on the DNA strand?
Enzyme helicase unwinds the DNA by breaking the bonds between nucleotides. Thus attaches itself at the nucleotides.
What protein adds complementary RNA nucleotides to provide a 3 end for which DNA can attach?
erre
What does the first nucleotide attach to because DNA polymerase can only add nucleotides to a pre-existing strand?
An RNA primer.
What does DNA polymerase 1 do?
DNA polymerase 1 is involved in replication when proofreading and repairing of the DNA sequence as well as removal of RNA primers placed by primase so that DNA polymerase 3 can successfully attach the complementary strand of DNA
Differences between DNA polymerase and RNA polymerase?
A polymerase is an enzyme that catalyzes the conversion of free nucleotides into a single strand. DNA polymerase differs from RNA polymerase in two major respects: * Like all enzymes, DNA polymerase is substrate-specific. DNA polymerase cannot extend a single strand of DNA; it needs at least a short segment of double-stranded DNA at the outset. * As its name implies, DNA polymerase incorporates deoxyribonucleotides into the new strand. RNA polymerase incorporates ribonucleotides. These differences mean that DNA polymerase is active when new DNA strands are formed, as in DNA replication, and RNA polymerase is active when new RNA is formed, as in transcription. Before DNA replication can begin, the two strands must uncoil, so that each can form a template for free nucleotides to attach to. But DNA polymerase cannot get started with a single strand! In vivo(in the cell) RNA polymerase, which is active in the presence of single-stranded DNA, catalyzes the incorporation of a handful of nucleotides into a new strand. The short length of double-stranded nucleic acid that is produced enables DNA polymerase to swing into action. This still leaves a potential difficulty: the nucleotides incorporated in the presence of RNA polymerase are the wrong sort (ribonucleotides). They are subsequently replaced by DNA polymerase. In vitro (during PCR, the polymerase chain reaction) a primer, specially synthesized in a laboratory, attaches to a specific segment of single-stranded DNA, and the DNA polymerase takes over from there. The primer consists of a short length of single-stranded DNA that uniquely complements a specific DNA segment that is targeted for amplification, for example for forensic analysis.In practice, there are several different DNA polymerases and RNA polymerases in an organism.
What are the elements of DNA polymerase?
DNA polymerase III (not DNA polymerase) is an enzyme that works in association with other enzymes during the replication of a DNA molecule. DNA replication begins when the enzyme, known as helicase unwinds a DNA strand. Helicase unwinds a DNA strand, thus, in the process, separating the two DNA templates. The result of the unwinding of the DNA molecule is the formation of a replication bubble. Once a DNA molecule is unwound, it is not stable. The DNA molecule is untwisted, broken and rearranged by an enzyme called topoisomerase in order to create stability at the ends of a replication bubble. In addition, the DNA replication bubble is further stabilized by a group of protein complexes known as single strand binding proteins.Once the DNA molecule is unwound and stabilized, an enzyme called primase assembles an RNA sequence that is complementary to the adjacent DNA template. The purpose of this initial RNA sequence is to provide a point at which DNA polymerase III can start to add nucleotides to the corresponding DNA template. Unlike RNA polymerase, DNA polymerase III requires an RNA sequence, which is known as a primer. DNA polymerase III can attach a nucleotide only to the 3 prime end of an existing nucleotide sequence. Once a primer is assembled by primase, DNA polymerase III begins its work of adding nucleotides to the 3 prime end of the primer.It is important to note that replication proceeds in two directions, since a DNA replication bubble consists of two DNA templates. Since DNA polymerase III proceeds in the three prime to 5 prime direction at one DNA template, it also has to proceed in the 3 prime to 5 prime direction on the other DNA template. Since the template run in opposite directions, the second template will consist of multiple primers and thus short segments of DNA. These short segments of DNA are known as Okazaki fragments. The Okazaki fragments are created by DNA polymerase three since it is only able to proceed in the 3 prime to 5 prime direction.After DNA polymerase III completes its work, DNA polymerase I begins to replace the RNA nucleotides of the primers with DNA nucleotides. Once DNA polymerase I replaces the RNA nucleotides with DNA nucleotides, DNA ligase joins the Okazaki fragments together and the result is a new DNA template.
Why do dideoxy nucleotides cause the DNA strand to stop elongating?
It doesn't contain an OHO bond so no other nucleotides can attach to it.
What is the attachment site for RNA polymerase?
according to information from http://www.rothamsted.ac.uk/notebook/courses/guide/trans.htm " if the RNA polymerase attaches to a special sequence called a promoter, an additional small protein, the factor sigma, will also attach to the polymerase and lock it on the DNA. The factor 'sigma' will only attach itself to the complex DNA / RNA polymerase when the RNA polymerase is attached to a promoter. Another hypothesis is that the factor sigma attaches to RNApol anyway and the enzyme is then able to slide along the DNA until it finds a promoter. It prevents detaching and speeds up promoter location, and decreases the affinity of RNApol for general regions of DNA. " Therefore, the answer seems to be, RNA attaches to DNA through a small protein called the factor sigma once the RNA polymerase attaches itself to a chain sequence called a "promoter". according to information from http://www.rothamsted.ac.uk/notebook/courses/guide/trans.htm " if the RNA polymerase attaches to a special sequence called a promoter, an additional small protein, the factor sigma, will also attach to the polymerase and lock it on the DNA. The factor 'sigma' will only attach itself to the complex DNA / RNA polymerase when the RNA polymerase is attached to a promoter. Another hypothesis is that the factor sigma attaches to RNApol anyway and the enzyme is then able to slide along the DNA until it finds a promoter. It prevents detaching and speeds up promoter location, and decreases the affinity of RNApol for general regions of DNA. " Therefore, the answer seems to be, RNA attaches to DNA through a small protein called the factor sigma once the RNA polymerase attaches itself to a chain sequence called a "promoter". role of sigmaActually RNA Polymerase can bind to DNA anywhere in the entire genome but sigma factor attaches to polymerase only when it is at promotor. sigma factor dissociates when polymerase crosses promotor. sigma factor stablises the pre initiatiation complex. Actually there are many promoter and many genes but which gene to be transcribed is decided by sigma factor.
Where does Helicase attach to on the DNA strand?
Enzyme helicase unwinds the DNA by breaking the bonds between nucleotides. Thus attaches itself at the nucleotides.
Why do you need to add primers DNA polymerase and nucleotides to your PCR mixture?
NEED OF PRIMER IN PCR-It is because the polymerase enzyme we use in the PCR only extend a DNA strand but not initiate its synthesis. So, to initiate the synthesis of DNA strand onto a template strand we require primers.
The enzyme that attaches nucleotides together by forming phosphodiester bonds between sugar and phosphate molecules during DNA replication is known as what?
The enzyme that attaches nucleotides together by forming phosphodiester is the DNA polymerase. The enzyme that breaks down a phosphodiester bond in an oligonucleotide is the phosphodiesterase.
What protein adds complementary RNA nucleotides to provide a 3 end for which DNA can attach?
erre
What is the name of the enzyme that would have placed nucleotides into the replicating DNA in the correct order?
DNA polymerases attach the free nucleotides and also proofread for mismatched pairs and replace them with the correct pair.
What determines where on the DNA molecule transcription begins and ends?
An RNA primer will attach to the unzipped DNA molecule signaling the beginning of transcription and transcription will occur until the DNA molecule is completely copied (the end is when there is no more DNA molecule to replicate).
