This is a versatile RNA molecule. In his famous book, RNA acts as an intermediary, such as genetic information from DNA to protein synthesis machinery. RNA also plays a more active role, performing many functions of a catalyst and recognition usually reserved for proteins. Indeed, the majority of RNA in cells found in the ribosomes - protein synthesis, our cars - and transfer RNA molecules are used to add each new amino acids to the growing protein. In addition, many small RNA molecules involved in regulation, treatment and disposal of the continuous traffic of messenger RNA. RNA polymerase from a great responsibility to create all these different RNA molecules. RNA plant RNA polymerase is a large factory with many moving parts. Shown here since the entry 1i6h AP, is that the yeast cells. It consists of a dozen different proteins. Together, they form a team that surrounds the DNA strands, relaxes and builds a string of RNA from information contained in DNA. After starting enzyme, the rise of faith in DNA copy of RNA polymerase RNA chains of thousands of nucleotides long. Accuracy As expected, RNA polymerase must be an exact copy of genetic information. To improve accuracy, correctness is a simple step to facilitate the RNA chain. Active site has been created to be able to remove nucleotides and add them to the chain growth. The enzyme normally float around nucleotide mismatch to add more if necessary as time for enzyme to remove them. This process is somewhat useless if necessary nucleotides were also dropped from time to time, but this is a small price to pay for the creation of better RNA transcripts. In general, RNA polymerase makes a mistake while adding 10,000 nucleotides, or about once in RNA chain is created.

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DNA topoisomerase:

DNA topoisomerase DNA supercoiling changes. Reduction of DNA-DNA topoisomerase. Type of DNA topoisomerase I drop a hair and DNA topoisomerase II-type knife with two teeth. DNA Topoisomerase regulates DNA supercoiling. Help topoisomerase DNA transcription and replication of DNA. And DNA topoisomerase I and DNA topoisomerase II, a DNA topoisomerase DNA topoisomerase III and IV. DNA topoisomerase: DNA topoisomerase is an enzyme that changes the supercoiling of double DNA. DNA topoisomerase acts for a short cut one or both strands of DNA. DNA topoisomerase type I series of cuts and the level of DNA topoisomerase II knife with two strands of DNA. Coil leave DNA topoisomerase and extends the DNA molecule. DNA topoisomerase helps regulate DNA supercoiling. DNA topoisomerase using DNA replication and transcription. Just as DNA topoisomerase I and DNA topoisomerase II, a DNA topoisomerase DNA topoisomerase III and IV. DNA topoisomerase III may regulate recombination. DNA topoisomerase IV regulates the separation of newly replicated chromosomes.

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Helicases

Helicases are a class of enzymes vital to all living organisms. They are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands (i.e. DNA, RNA, or RNA-DNA hybrid) using energy derived from ATP hydrolysis. Many cellular processes (DNA replication, transcription, translation, recombination, DNA repair, ribosome biogenesis) involve the separation of nucleic acid strands. Helicases are often utilized to separate strands of a DNA double helix or a self-annealed RNA molecule using the energy from ATP hydrolysis, a process characterized by the breaking of hydrogen bonds between annealed nucleotide bases. They move incrementally along one nucleic acid strand of the duplex with a directionality and processivity specific to each particular enzyme. There are many helicases (14 confirmed in E. coli, 24 in human cells) resulting from the great variety of processes in which strand separation must be catalyzed. Helicases adopt different structures and oligomerization states. Whereas DnaB-like helicases unwind DNA as donut shaped hexamers, other enzymes have been shown to be active as monomers or dimers. Studies have shown that helicases may act passively, waiting for uncatalyzed unwinding to take place and then translocating between displaced strands, or can play an active role in catalyzing strand separation using the energy generated in ATP hydrolysis. In the latter case, the helicase acts comparably to an active motor, unwinding and translocating along its substrate as a direct result ATPase activity.. Helicases may process much faster in vivo than in vitro due to the presence of accessory proteins that aid in the destabilization of the fork junction. Defects in the gene that codes helicase cause Werner syndrome, a disorder characterized by the appearance of premature aging.

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DNA polymerase

A DNA polymerase is an enzyme that catalyzes the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best-known for their role in DNA replication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand. The newly-polymerized molecule is complementary to the template strand and identical to the template's original partner strand. DNA polymerases use a magnesium ion for catalytic activity. DNA polymerase can add free nucleotides to only the 3’ end of the newly-forming strand. This results in elongation of the new strand in a 5'-3' direction. No known DNA polymerase is able to begin a new chain (de novo). DNA polymerase can add a nucleotide onto only a preexisting 3'-OH group, and, therefore, needs a primer at which it can add the first nucleotide. Primers consist of RNA and DNA bases with the first two bases always being RNA, and are synthesized by another enzyme called primase. An enzyme known as a helicase is required to unwind DNA from a double-strand structure to a single-strand structure to facilitate replication of each strand consistent with the semiconservative model of DNA replication. Error correction is a property of some, but not all, DNA polymerases. This process corrects mistakes in newly-synthesized DNA. When an incorrect base pair is recognized, DNA polymerase reverses its direction by one base pair of DNA. The 3'->5' exonuclease activity of the enzyme allows the incorrect base pair to be excised Following base excision, the polymerase can re-insert the correct base and replication can continue.

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