During which transcription step does RNA polymerase move along the DNA?

RNA polymerase moves along the DNA during the elongation step of transcription. This is the phase where the RNA polymerase enzyme synthesizes a complementary RNA strand based on the DNA template. As RNA polymerase advances along the DNA, it unwinds the double helix structure and adds ribonucleotides to the growing RNA chain, pairing them with the corresponding DNA bases. This synthesis continues until the polymerase reaches a specific termination signal in the DNA sequence, at which point the process concludes.

The initiation and termination stages serve different roles in the transcription process. During initiation, RNA polymerase assembles with transcription factors at the promoter region of the gene, while termination is the point where the synthesis concludes and the RNA molecule is released. Thus, it is in the elongation step that the actual movement and synthesis by RNA polymerase occur.