termination.txt

  1. Termination role
    • Determines length of protein by utilizing STOP codons (UAA, UAG, UGA)
    • tRNAs not needed to recognize STOP codon, but released factors are used (RF1, RF2, RF3)
  2. Role of RF1
    • Recognizes STOP codons: UAA
    • UAG
  3. Role of RF2
    • Recognizes STOP codons: UAA
    • UGA
  4. Role of RF3
    Stimulates RF1 and RF2 RELEASE after termination
  5. Recognition Stop Codon
    • RF1 and RF2 directly ID stop codons
    • recognized via HYDROGEN bonds linking mRNA nucleotides & the reading head of domain 2 of RF1 or RF2
    • Once recognized, release factors HYDROLYZE ester bond b/w polypeptide chain & tRNA at P site
    • polypeptide is released and RF3 is stimulated to release RF1 and RF2
  6. Role of RRF (only in prok)
    • Ribosome Recycling factor: protein responsible for SEPARATION of ribsoome
    • Increases efficiency of translation by recycling ribosomes
    • First, breaks subunits apart by entering P or A site
    • Utilizes GTP from an Elongation factor
    • IF-3 keeps subunit from reattaching
Author
rincrocci
ID
144036
Card Set
termination.txt
Description
termination
Updated