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GN 311 E4 > Translation > Flashcards

Flashcards in Translation Deck (6)
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1
Q

Feature of the Genetic Code

A
  • Triplet Code
  • Non-overlapping (reading frame sets the codon sequence)
  • Universal Code
2
Q

Codons to Know:

A

AUG - Start (Met)
UAG - STOP
UAA - STOP
UGA - STOP

3
Q

Prokaryotic Translation

A
  1. Small subunit identifies Shine-Dalgarno sequence (via initiation factors) and attaches at start codon
  2. tRNA-fMet attaches to the P-site on the small subunit
  3. The large subunit attaches
  4. Next tRNA attaches to the A-site
  5. Peptidyl transferase catalyzes formation of peptide bond
  6. The uncharged tRNA leaves the P-site via the E-site and the mRNA shifts down
  7. Stop codon recruits a GTP dependent release factor to separate the subunits and release the protein
4
Q

Wobble Rules

A

At the third base in a codon…

  1. Normal base pairing occurs
  2. G and U pair
  3. An I (on the anticodon only) will pair with A, U, or C
5
Q

Eukaryotic Translation Differences (6)

A
  1. Small subunit binds at G-cap via CAP binding proteins
  2. Usually the first AUG after the CAP
  3. Usually start codon within 40 bases of the CAP
  4. Start codon is optimally (but not always) in a Kozac sequence
  5. Poly-A Binding Proteins are present at 3’ end
  6. Initial tRNA-Met has a slightly different structure than tRNA-Met
6
Q

Differences in Mitochondrial Translation

A
  1. Initiates with fMet

2. Slightly different coding dictionary (relies on Wobble)