Spliceosomal E complex
spliceosomal e complex
The assembly of the spliceosome occurs in a stepwise manner. First, U1 snRNP is bound to the 5′SS of the pre-mRNA together with various proteins generating complex E.    The SF1 encoded protein recognizes the branch point sequence (BPS) at the 3' splice site during the formation of early complex E thereby pre-bulging the BPS adenosine, thought to facilitate subsequent base-pairing of the U2 snRNA with the BPS. U2AF2 interacts with SF1 and recruits the U2 snRNP to the spliceosome.    The entry of the U2 snRNP defines the branch-point and leads to the formation of the <a href='https://www.genenames.org/data/genegroup/#!/group/1504'>A complex</a>.