Transcription in Prokaryotes
X-ray crystallography analysis of core
- reveals shape: crab claw with a broad internal channel
- A pair of jaws grips DNA as it enters the enzyme
- Enzyme “melts” the 2 DNA strands at start site
- This makes the template strand accessible
- Polymerase can make several unsuccessful attempts
- After ~10 nucleotides, release of s factor
- Elongation complex that can move processively