L11: Transcription initiation in eukaryotes

eukaryotic genes

monocistronic

eukaryotic transcription

• mRNA undergoes additional processing 

• mRNA gets modified to produce mature mRNA

• nuclear export

nuclear export

• export mature mRNA from nucleus to cytoplasm before translation

• interconnected with mRNA modifications

• only properly matured mRNA can be transported

exons

parts of protein CDS that code for protein

intron

• nucleotide sequences that do not code for proteins

• must be removed before translation

3 modifications to become mature mRNA

• addition of 5’ cap

• splicing

• 3’ poly adenylation

bacteria co-transcription

• translation begins while transcription is still happening

• bacterial ribosome attaches to mRNA as soon as start codon becomes available

• direction of transcription and translation is the same

• 5’ to 3’