Unformatted text preview: bases) complementary
(3'UUAUU5') to the poly A site.
This polyA tail may prevent 3' degradation and increase the
half-life of the mRNA.
BIS101001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez ©2013
BIS101001, Spring 2013—Genes and Gene Expression, R.L. Rodriguez 22 Steps in Tailing of mRNA
A specificity factor, Cleavage and Polyadenylation
specificity Specificity Factor (CPSF), consists of three subunits,
each of which is an RNA-binding protein. Each of the
individual subunits will bind RNA non-specifically.
However, collectively, they recognize and bind specifically
to the AAUAAA polyadenylation sequence.
The Cleavage Stimulation Factor (CStF) an RNAThe Cleavage
binding protein, is required to stabilize the CPSF and
endonuclease. This endonuclease consists of two
components -- CFI and CFII. It cleaves the RNA.
Once these proteins have assembled, the mRNA is
cleaved 10-35 bases downstream of the AAUAAA
recognition sequence by the endonucleas...
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