single nucleotide change that causes a change in splicing
Cis elements are the sequecnes that are...
spliced
What are the two very highly conserved splice sites?
GU and A
R = ?
Purine
Y=?
pyrimidine
What are the two major trans factors?
5R Proteins (ser-arg)
sn RNPs
What lets the nucleus know where the exon is?
5R proteins
snRNPs recognize ...
introns and 5R proteins
what makes up spliceosome that splices pre-mRNA befor it leaves the nucleus?
5R proteins
Splicing in the nucleus can be ____ or ___transcriptional
co or post
Splicing is RNA ______, which involves 2 transesterifications.
catalysis
what is the benefit of RNA splicing?
no energy required for the chemical reaction (but trans factors need energy)
2 OH' is necessary for ______ because 2' deoxy won't work.
splicing
There is a nucleophilic attack of hydroxyl A on the....
branch pt. to phosphate
the branch point connects the 5' A, the 3' O on phosphate and the 2' oh to create a ...
lancet/lasso intron
What are the 6 steps in splicing?
1) 5R proteins define exons
2) U1 snRNP binds (proteins associated with 5R proteins and U1 RNA BPs at 5' splice junction of intron)
3) U2 snRNP Associates snRNP base pairs around branch point A (which is never base paired)
4) Triple snRNP associate with proteins around there, but mostly introns (U4/U6 snRNP: U4 bps to U6 near 3' of 5' exon and U5 snRNP: binds on intron close to 3' exon)
5) U4 unwindes from U6 (catalytic RNA that stars chemical mechanism)
6) Splicing begins
U3 not icluded in splicing because it is used for...