From Dna To Rna And Rna World Flashcards
Eukaryotic regulator sequences
Promoter proximal element(PPE)
UTR Strand for untranslated region. Before initiator codon there is 5’ UTR and after the Terminator codon there is the 3’ UTR
3’UTR is mostly responsible for stability Dna
5’UTR is mostly responsible for the effectiveness of translation
Enhancer
Önemli
Prokaryot ve ökaryotlardan sentezlenen kodon farklı
Ökaryotlar kesintili sentezlenir Prokaryotler kesintisiz sentezler
Eukaryotes promoter
TATA box:TATAAA
CAAT box
GC box:GGGCGG
October
Initiator:most frequently seen
Eukaryotic gene structure
RNA polymerase1 &Class 1 genes
RNA polymerase2 &Class 2genes:mRNAs
RNA polymerase3 &Class 3 genes:tRNAs and 5S rRNA
Prokaryotic repressor
Bind related operator
is encoded buy another gene which has its own promoter located on the upstream of operon
Stops transcription
Prokaryotic cells regulator sequences
Operator
Upstream elements(UP)
Enhancers
Operator:binds repressor protein/also has DNA itself-inactivate
Enhancer:activates transcription
Termination region pro
G-C rich region followed by 4-8U nucleotide repeats
Hairpin structure slows RNA polymerase
Transcriptional start site pro
Generally a Purin nucleotide
N letters refer to distance between those regions
Protomer structure pro
-10 region:TATAAT Pribnow box-unwinding
-35 region TTGACA-recognition
Responsible for gene expression
Ana rnalar(3) dışındakiler
Promoter prokaryotic
5’end
RNA polymerase binds to initiate transcription
Starting point
Prokaryotlara -10 ve -35 arasında
Ökaryotlarda more region
Stream
Upstream=5’
Downstream=3’
Basic elements in operon ökaryotlarda da aynı prokaryotlarda da
Promoter
Transcription start site
Coding sequence
Transcription termination region ökaryotlarda (polyadenylation signal)belirler
Operator
Prokaryotic gene
Operon
Gene
Coding sequence and regulatory sequence
Prokaryotic Rna polymerase
—Subunit
Scaffold
Promoter binding
—b b’ subunits
Catalytic center
—a(sigma) factor
Promoter specific binding
—holoenzyme
Core enzyme(consist of the subunits needed for catalytic activity)/5 subunit
Sigma factor(promoter specific binding)/transcription factor/promoter recognition
!!!!!!b’ dna binding
!!!!!!b elongation of rna
——Termination
Independent termination
Rho dependent termination
!!!!!!!
Coding strand:sense strand
Template strand:anti-sense strand
Eukaryotic RNA polymerase
——Required several initiation factor(general transcription factors) for promoter=called pre-initiation factor(PIC)
——transcription factor 2D binds TATA box
2A-2B bind
RNA polymerase together with 2F binds to this complex
Finally 2E-2H binds
Co-transcriptional modification
—5’capping
—splicing
—polyadenylation
Capping
Modified Guanine base to 5’ end of mRNA
—phosphate group is removed from the 5’end of the transcript
—GMP is added(guanylytransferase)
—modified by the addition of methyl group(methyltransferase)
Function of capping
Regulation of nuclear export
Prevention of degradation by exonucleases
ProMotion of translation
Splicing
—B globin çıkarılır
—splicingten sorumlu protein: spliceosome complexes they are U protein.this complexes also have RNA structures
RNP
ribonucleoprotein
Poplyadenylation(Poly A tail)
—Addition polyA tail to the 3’ end of mRNA
—CPSF(cleavage/ poliadenilasyon specificity factor)
CtsF( cleavage stimulation factor)
CF1 be CF2 (cleavage factors)
Multiple adenine nucleotides are added by polyA polymerase
