iGen3 05-11aiGen 05-1b

Post-transcriptional processing of mRNA; polyadenylation of 3' tail

[Left] The hnRNA runs 5'3' from the top left to lower right, where transcription terminates. [Right] Upon recognition of the AAUAAA signal, the 3' end is removed by an enzyme complex [CFI, II] at the cut site. Another enzyme complex [PA] synthesizes a poly(A) tail and ligates it to the free 3' of the pre-message.

Figure © 2010 PJ Russell, iGenetics 3rd ed.; all text material © 2014 by Steven M. Carr