Final answer:
In prokaryotic transcription, the transition from initiation to elongation requires the release of the sigma factor from RNA polymerase. This release allows the RNA polymerase to move along the DNA template, synthesizing mRNA during the elongation phase.
Step-by-step explanation:
The Transition from Initiation to Elongation in Prokaryotic Transcription
In prokaryotic transcription, the switch from initiation to elongation requires the release of the sigma factor (σ) from RNA polymerase. During initiation, the σ subunit of RNA polymerase is essential for recognizing the promoter region and initiating the process of transcription. Once the mRNA synthesis has begun, for elongation to proceed, the σ factor must dissociate from the polymerase. This event allows RNA polymerase to transition from the initiation phase and to move along the DNA template, synthesizing mRNA. This distinction helps clarify the difference between the prokaryotic mechanism and the more complex process in eukaryotic cells, which involves additional transcription factors and the separation of DNA strands affected by histones.
Elongation then continues with the core enzyme synthesizing mRNA at a rapid pace, unwinding and rewinding the DNA as necessary. The stable association between RNA polymerase and the DNA template ensures that the elongation phase is uninterrupted.