A sigma factor (σ factor or specificity factor) is a protein needed for initiation of transcription in bacteria. [ 1 ] [ 2 ] It is a bacterial transcription initiation factor that enables specific binding of …

The sigma factor was discovered in 1969 during attempts to clarify the nature of a bacterial RNA polymerase subunit in whose presence the transcriptional activity was specific and efficient …

A sigma factor is a subunit of bacterial RNA polymerases that determines the specificity of promoter DNA binding and enables efficient initiation of transcription. It works by binding to the …

2024年10月20日 · The sigma factor confers specificity, allowing the complex to recognize and bind to specific DNA sequences known as promoters. The structure of sigma factors is …

2025年1月14日 · Sigma Factor Variants. The diversity of sigma factors in bacteria reflects their adaptation to various environmental challenges. Each variant is tailored to recognize specific …

2024年11月23日 · Sigma factor proteins promote binding of RNA polymerase to promoter sites within DNA sequences to allow for initiation of transcription. Sigma factors are specific for the …

The default or “housekeeping” sigma factor of E. coli is σ70 or RpoD protein. Each alternative sigma factor is needed for the expression of a large suite of genes (typically 50 or more) that is …

2003年4月1日 · Members of the σ70 family of sigma factors are components of the RNA polymerase holoenzyme that direct bacterial or plastid core RNA polymerase to specific …

2015年6月26日 · Sigma factors are multi-domain subunits of bacterial RNA polymerase (RNAP) that play critical roles in transcription initiation, including the recognition and opening of …

Although the RNAP core is catalytically competent for RNA synthesis, the selectivity of transcription initiation requires a sigma (σ) factor for promoter recognition and opening.