IRESite record type: plasmid_with_promoter_and_putative_IRES_translationally_characterized
The shape of the nucleic acid molecule translated: linear
The quality of the mRNA/+RNA sequence: our_best_guess
The mRNA/+RNA description:
Putative in vivo bicistronic T7 transcript with CAT and GFP cistrons and 5'-UTR containing EMCV-R IRES
terminated by Tphi transcription terminator. The EMCV-R IRES is located between nucleotides 57-608 of the
putative mRNA and lacks the very rightmost 6 bases immediately preceding the initiator AUG codon of EMCV
polyprotein. A putative ERAV IRES is located in the intercistronic region.
The mRNA/+RNA sequence represented in the +DNA notation:
Credibility of mRNA sequence: end-to-end_sequence_reverse_engineered_and_should_match_experiment
The description of the protein encoded in this ORF: green fluorescent protein
The translational frameshift (ribosome slippage) involved: 0
The ribosome read-through involved: no
The alternative forms of this protein occur by the alternative initiation of translation: yes
The ORF absolute position (the base range includes START and STOP codons or their equivalents): 2018-2821
Remarks:
It appeared the ERAV 5'-UTR region downstream the poly(C) tract contains 5 AUG codons. The first 4 are in
pairs adjacent to each other, while the fifth is the most downstream and is alone. Three types of proteins
were detected from complete ERAV IRES 245-961, called Lab-GFP, Lb-GFP, GFP. The naming Lab and Lb reflects
the fact that possibly viral proteases Lab and Lb are initiated at those respective AUG codons.
The Lab-GFP, Lb-GFP, and GFP ORFs are located in the putative mRNA sequence at positions:
Lab-GFP: 1901-2821 [11.8% of first cistron, i.e. CAT]
1898-2821 [1.6% of CAT])
Lb-GFP: 1964-2821
1961-2821 [1.4% both together]
GFP: 2018-2821 [6.7% of CAT]
Also results shown in Fig. 7C show that when the 3'end of ERAV was deleted the Lab-GFP remained the
only translation product detected. It is not clear which fusion proteins remained when 5'-end of
ERAV IRES was deleted.