Promoters in E. coli were found using bacteriophages like λ and T7, which act very strongly to encode massive quantities of viral proteins. This same idea was expanded to eukaryotes, using adenoviruses (which infect eukaryotic cells). Viral genes express massive amount of proteins and a great model for finding examples of eukaryotic promoter sequences. Nuclear [...]

Initiation RNAP (RNAP) recognizes and binds to promoter region on dsDNA, forming the closed complex. Around the initiation site (+1), the DNA is unwound & becomes single-stranded; the RNAP/ssDNA structure is the open complex. The RNAP transcribes the DNA, but produces about 10 abortive (short, non-productive) transcripts which are unable to leave the RNAP because [...]

Eukaryotes have 3 RNAPs: RNAPI makes rRNA RNAPII makes mRNA RNAPIII makes tRNA & small RNAs Eukaryotes have 5 GTFs Tata Binding Protein (TBP) TFIIH FT TFIID TFIIB TFIIH Eukaryotic promoter has 4 parts B Recognition Element TATA box Initiator Downstream promoter element Initiation TBP recognizes and binds to the tatabox (-31 to -26). TBP [...]

E. coli RNA Polymerase is α2ββ’ω there are three eukaryotic RNA Polymerases. Binding of the RNA polymerase to the gene is highly regulated and requires lots of protein factors even for genes active in all cells. Transcription in eukaryotes requires the assembly of the RNA Polymerase into a very large initiation complex at the gene [...]

Gene expression in prokaryotes and eukaryotes is tightly controlled, mostly via transcriptional control whereby the initiation of transcription is highly regulated. In prokaryotes, the promoter is where repressors and activators bind and it is usually near the gene it regulates. In eukaryotes, the promoter is relatively far away and is bound by transcription factors (the [...]

In transcription, a complementary RNA sequence is made from a strand of DNA. In other words, transcription is the transfer of genetic information from DNA to RNA. It is similar to replication: it is antiparallel, 5′-3′ & there is complementary alignment of str&s. Transcription is performed by RNA polymerase (RNAP). Transcription has less & less [...]