Transcription/translation - Promoters
Promoters are DNA sequences located in the 5' region adjacent to the transcriptional start site. RNA polymerase and accessory proteins (transcription factors) bind to the promoter to initiate production of an mRNA transcript. Interactions of proteins at the promoter regulate gene actvity by activating or repressing transcription.
- ID: 15547
- Source: DNALC.DNAi
In most eukaryotic genes, coding regions (exons) are interrupted by noncoding regions (introns).
An image relating transcription and translation.
The majority of eukaryotic mRNAs contain a tract of A residues at the end. These polyA-tails are not encoded in the DNA. Rather, they are added to the pre-mRNA "post-transcriptionally" (after transcription). The end of pre-mRNA is cut by a specific enzyme
The diagram represents a single strand of DNA containing a gene, in purple. Remember this gene is "read" in the 5' to 3' direction to produce an mRNA.
Doctor Anil Malhotra discusses how transcription factors can turn genes on or off, possibly leading to increased or reduced risk of illness.
Professor Rusty Lansford explains that all genes are not expressed in the same levels in different cells; there is a lot of differential regulation.
James Watson talks about the Central Dogma: transcription and translation.
Professor Daniel Geschwind explains that cortical asymmetry refers to differences between the right and left side of the brain. This relates to gene expression.
RNA splicing removes non-coding introns and splices together exons.