mRNA Splicing

THIS IS INCREDIBLY USEFUL!!!!!!! THANK U!!! Sooo much better than my prof.

Totally just said that in a Russian accent and it was amazing.

Yeah, that is what happens. And I don't know why people are getting thumbs down for pointing that out because it is true. I will likely get thumbs down too for saying that. In order for the lariat to be formed...U1 and U2 MUST leave the spliceosome.

The U subunits ARE there. They make up the spliceosome. In fact, the U1 and U4 subunits are supposed to dissociate before the lariat is formed. Of course, they didn't mention that, BUT they did show the subunit corresponding to U1 dissociate from the mRNA.

i can sum up pre-mRNA processing simply: god doin' work. ;)

they dont say a damn thing about EJC

Hmmm... This isn't what I'm learning in my genetics class. We're being tuaght that 2'OH on the A site, with the help of splisomes that change the conformation of the mRNA, attacks the phosphodiester bond at the where the first exon and intron meet making the lariet. Next, again via conformation, the exposed 3'OH of the first exon attacks the phosphodiester bond at the remaining exon/intron connection. I guess I'll just go by what we learned in class.

I think this was implied by this video, but they used the term "cleaved" as a general catch-all. You're right, the bonds aren't cleaved by enzymes, but by nucleophilic attack via conformations. L'chaim!

I like how the ATP ---> ADP look in this animation.

its  very clear thanks a lot