{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}


Steps>>Transcription - snap easily meltable...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
*ALL SEQUENCES GIVEN FOR SENSE STRAND 5’ – 3’!* Prokaryotes » Initiation 1. Promoter site – 1) binding site for RNA polymerase [-35] σ factor, 2) site for unwinding [- 10 - AT-rich], 3) mark exact start point [+1 - A] 2. Holoenzyme [RNA Polymerase’s core enzyme + σ factor] – binds to promoter, σ factor falls off, unwinds DNA » Elongation 3. RNA Polymerase – reaches coding region to make mRNA [looks like sense strand], moving along template strand 3’ to 5’, adding ribonucleotides by base pairing 5’ to 3’ on mRNA strand [3’ end] 4. NusA – protein – binds to RNA Polymerase [core enzyme] to slow act of transcription, slow enough for ribosomes to keep up [coupled transcription and translation] » Termination [2 ways depends on gene at end] 5a. Rho-Dependent Termination rho-binding site on mRNA was transcribed into existence, rho [helicase – 5’ to 3’] breaks H bonds between RNA and DNA 5b. Rho-Independent Termination – 2 parts – 1) stem loop 2) string of U’s [A’s on DNA]; force of
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: snap + easily meltable U-A H bonds = rip RNA off of DNA 6. RNA Polymerase – dissociates after a) rho helps to dissociate b) loosing RNA Eukaryotes – no NusA, no σ factor, more variation [substitution of conserved sequences] » Initiation 1. Promoter site - 1) binding site for RNA polymerase [GC & CAAT boxes - TFs], 2) site for unwinding [-25 – TATA box], 3) mark exact start point [+1 - A] 2. Transcription Factors [TFs] – binds to promoter site at specific conserved sequences – each RNA P has a set of TFs 3. RNA Polymerase – recognizes/binds to complex of TFs [big complex of TFs & RNA P cover entire promoter » Elongation [3 different RNA Polymerases – specific to RNA] no NusA 4. RNA Polymerase – RNA P I [rRNA except 5s], RNA P II [mRNA], RNA P III [small RNAs – tRNA, 5s rRNA] – transcribes certain set of genes [3 RNA Ps 3 different categories of promoter] » Termination 5. Different for each RNA Polymerase...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online