BIOL213 Lecture Notes - Lecture 9: Transcription Bubble, Central Dogma Of Molecular Biology, Deoxycytidine Triphosphate
Document Summary
Prokaryote vs eukaryote: structure impacts on processes of the central dogma. Key elements of transcription: rna polymerase binds to genomic dna and locally denatures dna = transcription bubble, rna poly(cid:373)e(cid:396)ase sy(cid:374)thesises a (cid:272)o(cid:373)ple(cid:373)e(cid:374)ta(cid:396)y st(cid:396)a(cid:374)d of rna i(cid:374) the 5" 3" direction. No primer necessary: uses (cid:396)i(cid:271)o(cid:374)u(cid:272)leotide t(cid:396)iphosphate (cid:894)ntp"s(cid:895) p(cid:396)e(cid:272)u(cid:396)so(cid:396)s (atp, gtp, ctp, utp, not datp, dgtp, dctp, dttp (cid:894)dntp"s(cid:895, newly synthesised rna is co(cid:373)ple(cid:373)e(cid:374)tary to the 3" 5" (cid:894)te(cid:373)plate(cid:895) stra(cid:374)d(cid:895) Gene structure: genomic sequence contains promoter and terminator region, also contains a transcription initiation and termination site. In e. coli growing at 37oc, transcription proceeds at ~40 nucleotides/sec: rna/dna hybrid region only 8-12 bp long. Termination relies on rna secondary structure: rho-dependent terminators: additional (rho) protein factors involved. Rho independent terminators: no additional protein factors involved, relies on formation of a stem at self-complementary regions, 16-20bp upstream of termination site, formation of stem (hairpin) leads to dissociation of rna polymerase from template.
