pAcFRS.2.t1

RS/tRNA Pair Development Year
2015


RS Organism of Origin
Parent RS
RS Mutations
L65V
A167D

tRNA Organism of Origin
Parent tRNA
tRNA Anticodon
CUA
Other tRNA Mutations
R257G

RS/tRNA Availability
Can be purchased from Addgene Plasmid #73544
Used in what cell line?

RS/tRNA Additional Notes
The RS was evolved from the pAcFRS using MAGE (Multiplex automated genome engineering) in WT-E.coli .
It showed a 15-fold increased expression of GFP(3UAG) [ELP(Elastin-Like-Protein(30UAG)-GFP] compared to pAcFRS, the Selectivity testing showed a distinct preference for pAcF over pAzf. However, this was shown to diminish when exposed in a multicopy. The incorporation was shown to be relatively high after analysis of GFP fluorescence of ELP (30UAG)-GFP at 0.25mM, 0.5mM and 1mM of pAcF. This Assay also showed a modest kcat/Km improvement from pAcFRS with a 8.7-fold increase for tRNA aminoacylation.
By examing ELP(30UAG) and ELP(10UAG)-GFP with shotgun liquid chromatography(LC)-tandem MS showed pAcF incorporation >95% for all peptide and producing full length protein >97% of time.
The changes to the binding pocket had allowed to incorporation of the following ncAA at the same level as pAcF: L-4-Methoxy-phenylalanine(MeY) as assayed by GFP(3UAG) fluorescence. While these were incorporated at higher rate: L-4-Iodo-phenylalanine (4IF), O-tert-Butyl_L_tyrosine(BuY) and 4-phenyl-phenylalanine(phF) as assayed by GFP(3UAG) fluorescence.