RNA Transcription
RNA Transcription
CONVERTS INFORMATION IN DNA TO RNA
- Protects original information
- Multiple RNA copies allow for more protein to be produced
Transcription factors
Proteins which bind the promoter and recruit the RNA polymerase
Template strand
Strand of DNA in which the gene to be transcribed is located
THREE STEP PROCESS:
Initiation
- Promoter recognized by transcription factors
- RNA Polymerase II recruited by the transcription factors
- Transcription begins and continues 3' to 5' along template strand
Elongation
- Complementary RNA nucleotides added to the growing RNA strand (uracil instead of thymine in the RNA strand)
Termination
- Polyadenylation signal in the transcribed RNA signals proteins to cut it from the polymerase
- Newly formed RNA is called Pre-mRNA because it still needs to be processed
- RNA Polymerase eventually falls off the template strand
- Help with the export of the mRNA from the nucleus
- Protect the mRNA from degradation in the cytoplasm
- Help facilitate proper translation
Prokaryotes:
- Only one polymerase isoform
- Occurs in the cytoplasm (since no nucleus)
- RNA polymerase recognizes the promoter sequence
- RNA polymerase recognizes the terminator sequence
- No additional processing of mRNA