WEEK 1 Flashcards
What is mis-regulation?
Where genes are up-regulated or expressed where they shouldn’t be
What does RNA require to open up DNA
Magnesium ions and the co-ordination of NTP’s
What % of sequences are coding in the gene
2%
Why does RNA need GTF’s
RNA cannot recognise coding regions of genes, so has to be recruited by GTF’s
What is a TATA box?
A sequence about 20 bp above the promotor. Shows where DNA can be read and coded
What happens if a mutation alters the TFIIB
It can alter the start point of transcription
How does TFIIH start transcription
It has kinase activity that can phosphorylate the C terminal domain, making it hydrolysed and attaching the RNA II to start transcription
What does TFIIE do?
Stabilises the transcription bubble to keep it open and allow for transcription to work
What does CTD do?
CTD being hydrolysed allows a landing site for many other proteins to work on transcription.
Also recruits splicing factors
What do capping proteins do
Protect the RNA as its sensitive
What are cis-regulatory sequences
Different factors on the DNA molecule that can influence what happens at the transcription start site.
What is the dimerisation domain
Where transcription factors can interact with each other.
homodimer
2 of the same transcription factor
Whats a benefit of heterodimerisation of TF
Can recognise different sequences in the gene.
What happens if an inhibitory factor binds to a TF
The gene will not be transcribed as one TF is not enough.
What is an insulator DNA sequence.
prevent transcription factors from influencing any other gene
Why must introns be removed?
They often contain stop codons and would stop translation too early
What is a spliceosome
a protein complex that facilitates RNA splicing
How are introns recognised?
Splice site consensus sequences
What is the product of pre-mRNA splicing
excised intron lariat
What is alternative splicing
mRNA can have different splicing patterns so different exons may be included in each round of splicning, allowing one gene to code for multiple proteins
how can protein isoforms be made
homologous genes or alternative splicing
