How are transcription factors controlled?
Transcription factors include a wide number of proteins, excluding RNA polymerase, that initiate and regulate the transcription of genes. Other transcription factors bind to regulatory sequences, such as enhancer sequences, and can either stimulate or repress transcription of the related gene.
Do prokaryotes use transcription factors to control transcription?
Sequence-specific transcription factors are considered the most important and diverse mechanisms of gene regulation in both prokaryotic and eukaryotic cells (Pulverer, 2005).
How are prokaryotes controlled?
Prokaryotic gene expression is primarily controlled at the level of transcription. Eukaryotic gene expression is controlled at the levels of epigenetics, transcription, post-transcription, translation, and post-translation.
What is the function of transcription factors?
Transcription factors are proteins that bind to the upstream regulatory elements of genes in the promoter and enhancer regions of DNA and stimulate or inhibit gene expression and protein synthesis. They play critical roles in embryogenesis and development.
What are examples of transcription factors?
Mechanistic
| Examples of specific transcription factors | ||
|---|---|---|
| Factor | Structural type | Recognition sequence |
| SP1 | Zinc finger | 5′-GGGCGG-3′ |
| AP-1 | Basic zipper | 5′-TGA(G/C)TCA-3′ |
| C/EBP | Basic zipper | 5′-ATTGCGCAAT-3′ |
What are transcription factors How do they affect transcription?
Transcription factors are proteins that help turn specific genes “on” or “off” by binding to nearby DNA. Transcription factors that are activators boost a gene’s transcription. Repressors decrease transcription.
How is transcription controlled regulated in prokaryotes and eukaryotes?
As already discussed, transcription in bacteria is regulated by the binding of proteins to cis-acting sequences (e.g., the lac operator) that control the transcription of adjacent genes. The eukaryotic regulatory sequences are usually ligated to a reporter gene that encodes an easily detectable enzyme.
What initiation and termination factors are involved in transcription in prokaryotes?
Sigma factor is responsible for initiation of transcription. Rho factor is responsible for termination of transcription.
