Transcription: The Basics
Polymerase lays down complementary RNA
- new strand 5' —> 3' direction
- template DNA in 3' —> 5' direction
- unwinds DNA temporarily as it travels along
- essentially irreversible
- exergonic pyrophosphate hydrolysis
- must have proper match to template
- DNA helix closes behind polymerase
- only few (~8) RNA bases attached at a time
- Bacteria incorporate 50 - 100 nucleotides/sec;
- genes in cell transcribed at same time by numerous polymerases