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| Unit 2: Demos |
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Promoter strength (3c) Transposons: Spam from the Dark Ages (optional) Recombinant DNA and gene cloning PCR (supplementary): What the heck is PCR? Gel electrophoresis (supplementary): Genome
mapping (supplementary) DNA profiling (supplementary): Disclosure
of variation - Now that the sequence of the human genome
is almost complete, the human genomics community is turning its
attention towards what, genetically speaking, makes people different. Gene Therapy Genetic engineering: Flower
Power Takes on Land Mines (story with image) |
What Is The Role Of RNA Polymerase In Transcription? RNA polymerase is a complex enzyme that plays multiple roles in the process of transcription:
DNA contains initiation sites called promoters that specifically bind RNA polymerase and determine where transcription begins. In prokaryotic cells, two sequences on the 5' (upstream) side of the first nucleotide to be transcribed are important (See Fig. A). One has the consensus sequence TATAAT and is centered at –10 (10 nucleotides on the 5' side of the first one transcribed, which is denoted by +1). The other, the –35 region, has the consensus sequence TTGACA. Eukaryotic genes encoding proteins have promoter sites with a TATAAA consensus sequence centered at about –25 (Fig. B). Many eukaroytic promoters also have a CAAT box centered about –75. Transcription of eukaryotic genes is also facilitated by enhancer sequences that can be quite distant from the start site.
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