A transcription bubble is a localized region of separated DNA strands within a transcription complex, exposing a template for RNA synthesis. During bacterial initiation, promoter binding and DNA opening produce an RNA-polymerase complex positioned to initiate the transcript [1]. Regulatory proteins can alter promoter recognition and the transitions leading to productive initiation [2]. In an elongating complex, the template strand enters the polymerase active site, where the growing RNA forms a short hybrid with DNA before emerging from the enzyme [3][4]. The displaced nontemplate strand follows a separate path. Structural elements of RNA polymerase coordinate the two bubble boundaries, with downstream strand separation and upstream strand reannealing accompanying progression of the transcription complex along the DNA [5].
- RNA polymerase
- DNA strand separation
- open promoter complex
- RNA–DNA hybrid
RNA Research and Splicing·Molecular Biology·Biochemistry, Genetics and Molecular Biology·Life Sciences
References
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