20 Flashcards
what is the proteome
all of the proteins found in a particular cell
what’s the importance of the AATAAA region
tells polymerase to add A tail
where is the proximal promoter found
about 30 nucleotides upstream from transcription start site (includes the TATA box)
where are enhancers found
upstream of coding region or in introns
what’s the size of RNA pol II
550 kDa
what kinds of molecules are activators and repressors? where do they bind=
they are DNA binding protein. activators bind enhancers and repressors bind repressors
what happens when activators bind enhancers
coactivators allow chromatin structures to be relaxed by acetyl methylate phosphorylate histones or move them out of the way
what modification occurs that a allows RNA pol to leave promoter and start transcribing gene
c terminal domain of its tail gets phosphorylated
how many nucleotides long is the transcription bubble
20
what’s TFIIH
helices part of preinitiation complex, allows for local unwinding of DNA complex. uses ATP
why does RNA use uracil pluton que T
bc it requires less energy to make
where are CstF (cleavage stimulatory factor) and CPSF (cleavage and polyadenylation specificity factor) found?
on c terminal domain of polymerase
what two factors are necessary for termination and why
CstF (cleavage stimulatory factor) and CPSF (cleavage and polyadenylation specificity factor).
CPSF binds poly a tail and CstF binds GU rich region
By binding, they recruit exonuclease which cuts growing strand of RNA and RNA polymerase can then synthesize poly a tail (200 nucleotide long)
what’s the role of the capping enzymes (methyl transferases)
add 7 methyl guanosine unit on 5’ attaching to fist nucleotide via 5’-5’ triphosphate linkage to stop transcription
why is 5 cap import
prevents degradation
recognised at trasnlation
