introns are - and - in simple Eukaryotes like yeast
common; very large
introns are - and - - in higher Eukaryotes like humans
5' GU; branch sequence A; 3' AG
Splice sequence- conserved pattern:
2' OH; 5'
Lariat model: 1) - -- attacks the - splice site
3' OH ; 5'
Lariat model: 2)- -- (deposited by step 1) attacks the - splice site
Lariat model: 3) intron is removed, exons joined by - bonds