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Taq Polymerase. By: Rachel and Justin. General Protein Synthesis. http://gleesonbiology.pbworks.com/w/page/7537902/M4. RNA is copied from DNA through transcription – a process by which the double helix strand is unwound, then copied onto a strand of RNA.
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Taq Polymerase By: Rachel and Justin
General Protein Synthesis http://gleesonbiology.pbworks.com/w/page/7537902/M4
RNA is copied from DNA through transcription – a process by which the double helix strand is unwound, then copied onto a strand of RNA http://hyperphysics.phy-astr.gsu.edu/hbase/organic/transcription.html
That mRNA then travels outside of the nucleus and into a ribosome • The ribosome is like a translator to translate the mRNA into a polypeptide chain. • tRNA with an amino acid on one end, and an anticodon on the other, enters the ribosome, and matches with the mRNA, copied from the DNA. • As the anticodons and codons match up, the amino acids break away in a polypeptide chain. http://www.biologycorner.com/bio2/genetics/notes_transcription_translation.html
Enzymes • Enzymes catalyze specific reactions. Each one has an active site that perfectly fits the substrate that the enzyme catalyzes the reaction for. Basically Form Fits Function http://www.buzzle.com/articles/how-do-enzymes-work.html
Taq Polymerase • Taq Polymerase is a protein composed of a single polypeptide chain consisting of 832 amino acids, taken from the bacterium ThermusAquaticus, which is thermophilic, meaning it its optimal temperature is extremely high for living organisms; about 75-80°. Bacterium ThermusAquaticus http://en.wikipedia.org/wiki/Taq_polymerase http://en.wikipedia.org/wiki/File:Thermus_aquaticus.JPG
Structure • It has three domains; a 5′ to 3′ nuclease domain • An inactive 3′ to 5′ exonuclease domain • And a 5′ to 3′ polymerase domain • The inactive exonuclease domain and the polymerase domain together are called the Klentaq fragment. • http://www.ncbi.nlm.nih.gov/pubmed/8717047 • http://sthor.myweb.uga.edu/bcmb8010/report.pdf
Metabolic/Physiological Function • The “palm” section catalyzes the phosphoryl transfer reaction, the transfer of the phosphoryl group (PO3) from a phosphate ester or anhydride to a nucleophile • The “fingers” interact with the incoming nucleoside triphosphate and the template it is being matched to • The “thumb” helps to position the oncoming DNA and enzyme in order to properly carry out the function • The “wrist” section is basically the nuclease domain • http://sthor.myweb.uga.edu/bcmb8010/report.pdf • http://www.els.net/WileyCDA/ElsArticle/refId-a0000608.html
History • ThermusAquaticus was unintentionally discovered by Thomas D. Brock when he was examining mushroom samples from Yellowstone National Park • Taq polymerase was discovered in the 1980’s by Kary Mullis in 1983 when he was adding DNA polymerase to various strands of DNA which greatly increased the amount of strands presents. • http://www.genetics.org/content/146/4/1207.full.pdf • http://sthor.myweb.uga.edu/bcmb8010/report.pdf • http://pl.wikipedia.org/wiki/Kary_Mullis
Industrial Purposes - PCR • Taqpolymerase can withstand temperatures needed to produce the best effects in this machine, so scientists can run many PCR cycles automatically. • PCR involves denaturing, annealing and replication steps, usually repeated 20 to 30 times. Denaturing separates the double-stranded DNA into single strands. In the annealing step, primers bind to the segments of DNA to be copied. Taq polymerase goes to work in the replication step: the polymerase builds each single strand of DNA marked by a primer into a new, double-stranded DNA segment. • Genetic testing • Infectious disease applications- PCR is used in slow growing bacteria to allow more DNA to be tested for research http://en.wikipedia.org/wiki/Applications_of_PCR
PCR Uses • Genetic testing • Infectious disease applications- PCR is used in slow growing bacteria to allow more DNA to be tested for research • Organ transplantation • Tissue typing • Genetic fingerprinting in forensics • http://en.wikipedia.org/wiki/Applications_of_PCR • http://www.whitcoulls.co.nz/book/organ-transplants/5730966/
Catalyzed Reaction • Taq Polymerase catalyzes reactions in the nucleus, pertaining to DNA replication and repairs • Taq polymerase utilizes a DNA polymerase domain to catalyze the addition of dNTP to the 3′ hydroxyl terminus of an RNA primer and a 5′ nuclease domain to cleave the downstream, single-stranded 5′ nucleotide displaced by the growing upstream strand http://www.pnas.org/content/102/49/17646.long
Video • http://www.youtube.com/watch?v=_PRUfJBzu-A Better explanation here, trust us.
Environmental Factors • Taq polymerase can function at very high temperatures. Sometimes low temperatures cause this enzyme to denature or not function properly. • Some bacteria is harmful to the function of this enzyme • Melanin can also affect it • Some types of dye or fabrics also inhibit taq polymerase’s function http://www.nfstc.org/pdi/Subject03/pdi_s03_m01_02.htm
Conclusion • Taq Polymerase is used in DNA replication and repairs. It follows the normal function of all enzymes. Taq Polymerase catalyzes the DNA reactions. It is used industrially by the PCR, or the Polymerase Chain Reaction, which is used for genetic testing, fingerprint testing, organ testing, and infection diagnosing. Overall, this enzyme is very useful and helpful in today’s world.