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 and although it is referred
to as 1-961 it consists of only 956 bp.
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): 2260-3063
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 1-961, 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: 2143-3063 [11.8% of first cistron, i.e. CAT]
2140-3063 [1.6% of CAT])
Lb-GFP: 2206-3063
2203-3063 [1.4% both together]
GFP: 2260-3063 [6.7% of CAT]
These data were obtained for pE1(245-961) plasmid transcripts but should be applicable to pE1(1-961) as well
(Fig. 5B).