Amniocentesis - DNA/RNA replication/translations Flashcards
DNA pol I
prok DNA pol, poly, proof, exo 5’ to 3’
DNA pol III
prok DNA pol, poly, proof
DNA pol a
euk DNA pol, primase, poly
DNA pol b
euk DNA pol, poly, repair
DNA pol delta
euk DNA pol, primase, poly, proof on LAGGING
DNA pol epsilon
euk DNA pol, primase, poly, proof on LEADING
RnaseH
euk removal of primer during DNA pol
Start codon
AUG - meth
Stop codons
UAA, UAG, UGA
DNA pol gamma
euk DNA pol, primase, poly, proof in MITOCHONDRIA
Primary active sites on tRNA
CCA and anticodon
Aminoacyl-tRNA synthetase
Attaching AA to the sugar -OH on tRNA through ester linkage, cost equiv of 2 ATP, have proofreading
Prok Ribosomes
70S = 30S (16S rRNA+prot) + 50S (23S rRNA+5S rRNA+prot)
Euk Ribosomes
80S = 40S (18S rRNA+prot) + 60S (5.8S rRNA+28S rRNA+prot and 5S RNA from other place)
Ribosome sites
A - aminoacyl-tRNA
P - peptidyl transferase - peptide bond formation
E - exit
eIF2
euk Initiation factor 2 bound to GTP binds tRNA-met-i
eIF3
euk Initiation factor 3 bound to 40S euk smaller ribosome subunit, anti-associtation, binds to eIF2-tRNA-AA-GTP
eIF1 and eIF1a
euk Initiation factor 1 binds to eIF2-AA and eIF3-40S
eIF4
binds 5’ end to mRNA and brings into ribosomal small unit, leading to scanning of mRNA looking for first AUG, needs ATP
When is eIF2-GTP released?
When start codon is found, eIF2-GTP is hydrolyzed to eIF2-GDP and released from small subunit
eIF5B
Uses GTP to bring in large ribosomal subunit, eIF3 leaves
PAB
Poly-A binding protein, part of eIF4 that binds to poly-A tail of mRNA
eIF4E
Binds to 5’ End of mRNA
eIF4G
Grabs hold of PAB and eIF4E and holds mRNA in circular form
eIF4A
used ATP facilitates scanning of mRNA for AUG codon
RAD51
Heterologous Repair - binds to injury and used to scan for new template
What id the only tRNA that can go directly to the p-site?
Met-tRNA-i
EF1a-GTP
Elongation factor 1a-GTP can recognize activated tRNA-AAs and shuttle them to a-site until correct anticodon is found, when found EF1a-GTP hydrolyzed to EF1a-GDP and released
How is EF1a-GTP regenerated?
EF1betagamma facilitates release of EF1a-GDP and GTP reinteracts with EF1a, after activation EF1a-GTP can pick up another activated tRNA
Direction of peptide formation
N to C
Ribosomal peptidyl transferase
Ribozyme that transfers AA from carrier tRNA to alpha amino group of AA in A-site forming peptide bond
EF2-GTP
Elongation factor 2 moved mRNA and dipeptidyl tRNA from A site to P site through EF2-GTP hydrolysis to GDP
eRF1
recognizes stop codon by release factors and hydrolysis of peptide chain and disassembly of ribosomal protein complex
eRF3-GTP
recognizes stop codon by release factors and hydrolysis of peptide chain and disassembly of ribosomal protein complex, GTP to GDP
IF1-3
Prok initiation factors with same functions as eIF1-3
Formelyn
Formilated meth used as start codon in prok
Shine-Dalgarno
Prok 16S rRNA is complementary to SD region and when it lines up translation begins, saves energy because no scanning for start codon (save 1 ATP)
EF-Tu
Prok equiv to EF1a
EF-Ts
Prok equiv to EF1betagamma
EF-G
Prok equiv to EF2
RF1 and RF2
prok release factors that recognize STOP codons (UAA, UAG, UGA)
RF3-GTP
promotes release of RF1 or RF2 in prok, and GTP is hydrolyzed to release RF3
RRF
ribosomal recycling factors promotes dissociation of ribosomal complex in prok
How is EF2-GTP regenerated?
EF2beta facilitates release of EF2-GDP and GTP reinteracts with EF2
How can eIF2 be regulated?
Phosphorylation of eIF2 when its bound to eIF2b wont allow the complex to dissociate and eIF2-GDP cant be recharged to GTP, GLOBAL REGULATION OF TRANSLATION
How can eIF4e be regulated?
eIF4e is usually bound to 4E-BP which inactivates it. Under normal conditions eIF4e is phosphorylated and then detaches to bind to 5’ end of mRNA. Regulations of phosphorylation will cause GLOBAL REGULATION OF TRANSLATION
mRNA masking
complex can hide start codon and keep other interactions that would keep it from being translated. mRNA SPECIFIC REGULATION OF TRANSLATION
ADP ribosylation of EF-2
Mechanisms for controlling elongation in euk.
Recoding of UGA codon to selenoproteins
Change UGA to selenoproteins and presence of SECIS element prevents the stop codon from being read, specialized elongation factor
Puromycin
resembles Aminoacyl-tRNA - affects both prok and euk by plugging up A-site
Cycloheximide
inhibits peptidyl transferase preventing elongation in euk
Streptomycin
Prevents binding at P-site by binding to 30S (S12) subunit in Prok
Tetracyclines
Prevents binding at A-site by binding to 30S (S12) subunit in Prok
Chloramphenicol
Inhibits peptidyl transferase to keep polypeptide from forming, affects euk mitochondria and prok because similar machinery
Erythromycin
Blocks tunnel of 50S subunit in prok