Amazon Contextual Product Ads

Sunday, 25 November 2007

genetic engineering (5)

RA synthesis
5'->3' direction
no primer
DNA dependent RNA polymerase (RNA polymerase)
anticoding strand, template strand

promotor -RNA polymerase (alpha, beta, delta)binding site - 5' ustream to transcription initiation site (+1)
termination -Rho protein, inverted repeat
prokaryote - -35 and - 10 consensus sequence- Pribnow box
Eukaryote -75 CAAT box -5'GGNCAATCT3', -25 TATA box,Hogness box - 5' TATAAA3'
higher organisms
RNA pol 1 polA-rRNA except 5 SrRNA, super repeat promotor
RNA pol2 polB-mRNA- normal promotor, AAUAAA-polyadenylation signal (20-30 b before 3')
RNA pol3 polC-tRNA, 5srRNA, scRNA, internal control region (ICR)

Posttranscriptional modification
tRNA- methylation, oxygen-->sulfur
rRNA-methylation, shortening
-7 methyl guanosine capping
-poly Adenylation tail
-splicing -exclude intron-snRNPs, some self splicing

alpha interferon - no intron
beta globin -2 intron
factor VIII-25 intron
human thyroglobulin- > 40 intron

No comments: