21 Flashcards
(22 cards)
occurs when a stop codon doesnt function as a stop codon but leads to the incorporation of an amino acid
programmed sto codon read through
occurs when the reading frame shifts during decoding
programmed frameshift
what occurs when a stop coodn is misread by an aatRNA
nonsense suppression
stop codon readthrough
a stop codon is misread by a mutant tRNA that has mutations in the anticodon of the uRNA
nonsense supression
a true stop codon does not function as a stop codon bc of features in the mRNA that encourage misreading at that loaction by a regular aatRNA
stop codon read through
nonsesnse mutation
normal codon is mutated to a stop codon
what does MuLV do
programmed sto codon read through- nonsense suppression
stop codon for MuLV and anticodon and what aa is used
UAG
anticodon is CUG for gln
misread due to pesudoknot
stop codon reprogramming permits what
non standard amino acids
U
selenocystein
selenocysteine code
UGA
O
pyrrolysine
pyrolysine code
UAG
what causes misreading of selenocystein
SECIS loop immediately downsteram of UGA
how is selenocysteine meade
using a tRNAsec charged with serine by SerRS and converted using selenocysteine synthase
brought by SelBwhich is like EFTu and recognizes SECIS stem loop
selenocysteine in euk
SBP2 binds to the SECIS loop and eEFSec brings the sectRNAsec tot he ribosome
where is pyrolysine found
in the active site of methyl transferase enzymes in some methane producing bacteria and not found in humans,
REQUIRED FOR CATALASYS IN THOSE ENZYMES
pyrolyssien anticodon
5’-CUA-3’
pyrolyssine is made how
PylRS and its own tRNA
how can we use the pyrrolysine tRNA synthase tRNA pair
genetically encodes a plethora of noncanonical AA through stop codon reassignment
what uses frameshift mutations
rous sarcoma virus to synthesize Gagpol protein
gagpol synthesis through frameshifts
90% produces Gag through UGA stop
10% produces gagpol due to -1 frameshift due to pseudoknot- slippery- AAU pairs with UUA(normal) or UUU (-1)
