Term
| Eukarayotic v. Prokaryotic |
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Definition
| Eukaryotic mRNA is spliced then capped and and adenylated,whereas Prokaryotic mRNA is not spliced and can also by polycistronic |
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Term
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Definition
- Made of 50 differnet proteins and several RNAs
- Eukary ribos can add 2 AA/sec and prokary add 20/sec
- Activity mostly conducted by rRNA
- 1 large and 1 small subunit fit together, mass of several mill daltons
- Subunits combine together on mRNA, otherwise seperate |
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Term
| Ribosome has X binding sites |
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Definition
| 4; 1 for mRNA and 3 for tRNA E (exiting tRNA), |
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Term
| The peptide bond is forms between _____ and ______ by the aid of ______ from ______ |
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Definition
| Incoming aminoacy-tRNA at the A-site and the peptidyl-tRNA in the P site by the aid of peptidyl transferase in the large subunit |
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Term
| Steps of Initiating Protein Synthesis |
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Definition
1) Binding of initiater tRNA to small ribo subunit
2) Binding of 5' end of mRNA to the small ribosomal subunit
3. Identificaton of the initiation codon
4. Association of the large ribosomal subinit
5. Formation of the first peptide bond |
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Term
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Definition
1) Always carries methionine
2) Has a unique nucleotide sequence that allows it to be distinguished
- Loaded onto ribos subunit complexed with eIF2 and IF2 |
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Term
| the ____ subunit binds at the ____ end of mRNA. The 5' end is recongized by presence of ____ and _____ |
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Definition
small subunit binds at the 5' end...
by presence of eIF4F and eIF4G |
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Term
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Definition
| Binds to 5' cap, needed to load mRNA |
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Term
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Definition
| Couples 5' end of mRNA with the 3' poly A tail; key for initiation and rate of translation |
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Term
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Definition
- Subunit scans mRNA looking for first AUG
- Movement is aided by ATP-powered IF helicases that deal with secondary mRNA structure
- If the fist AUG does not have the Kozak sequence between ACC and G then small subunit moves on. |
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Term
| Prokaryotic initiation sequwnce |
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Definition
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Term
| Eukaryotic initiation sequence |
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Definition
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Term
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Definition
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Term
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Definition
- Once AUG is recognized, TFs are released and large subunit binds
- tRNA is bound at P-site and A-site is vacant and the ribosome is ready to initiate protein synthesis |
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Term
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Definition
| complexs with charged initiator tRNA and binds to the small subunit |
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Term
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Definition
| swaps GTP in for used GDP on the eIF2 so it will be availible for next cycle |
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Term
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Definition
| complex that binds to the 5' cap and helps the preinition complex, part of protein helps to unwind mRNA and part forms link between 5' end and polyA |
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Term
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Definition
1)tRNA binding
2) Peptide ond formation
3) Large subunit translocation
4) Small subunit translocation |
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Term
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Definition
| E-Tu-GTP binds to A-tRNA to forma complex which moves into A-site until there is an appropriate match |
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Term
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Definition
| Complex of EF-Tu-GTP and aminoacyl tRNA is bent to allow codon/anti-codon interaction but no pep bond formation |
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Term
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Definition
| Baceterial EF, catalyzes transolcation by hydrolizing GTP |
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Term
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Definition
| Eukaryotic EF that catalyzes translocation via hydrolysis of GTP |
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Term
| Termination Release Factors |
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Definition
Proteins that recognize stop codons, bind to the A site, forcing peptidyl transferase to catalyze addition of water instead of AA to peptidyl-tRNA
Additional release factors catalyze dissociation of ribo subunits |
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Term
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Definition
| Large assemblies of many ribosomes spaced as close as 80 nucleotides apart on mRNA |
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Term
| Translation Regulation Mechanisms |
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Definition
MicroRNA's
TF Activity
RNA-binding proteins |
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Term
| Regulation of IF Activity |
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Definition
1) GF Stim; triggers phosphorylation of eIF-$E increasing binding to 5'cap and increasing translation rate
2. GF deprivation phosphorylates eIF-2 which tightens its hold on GDP preventing recycling |
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Term
| Aconitase as example of RNA binding protein and translation |
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Definition
- Iron Starvation; binds to 5' ferritin and blocks translation also binds to 3' of tranferrin recpetor transcript, increasing transferrin receptor transcript stability
Excel iron; iron binds to aconitase and changes conformation. Cant bind to ferritin transcript so ferriten is made, cant bind to tranferrin receptor transcript so transferrin receptor transcript is unstable and it is not made |
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Term
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Definition
| Binds iron and stores it in the cytoplasm |
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Term
| Transferrin and Transferrin Receptor |
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Definition
| Binds iron outside the cell and functions in iron transport, the receptor binds to transferring and transferrin-iron complexes and brings them into the cell |
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Term
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Definition
| short non coding, base-pair with specific mRNAs and regulate stability or translation |
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Term
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Definition
- Internal Ribosome entry site, cap independant initiation of translation in Eukaryotes and many viral RNA
- Allows the translation of selected mRNA's at high rate when translation of cap-dependant mRNA is down
- Many viruses will block cap-dependant translation, effectively taking over
- Mitotic and cell death products rely on IRES |
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Term
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Definition
| Inhibit bacterial protein synthesis |
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Term
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Definition
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Term
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Definition
| Prevents transition from initiating complex to chain elongating ribo |
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Definition
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