Abstract: After the genomic RNA was extracted from purified Ectropis oblique picornavirus (EoPV) virons with Trizol, cDNA fragments complementary to EoPV RNA were synthesized using reverse transcriptase and added poly (dT) tail. The 5′terminus was amplified by two step PCR. After being cloned and sequenced, the 5′UTR of EoPV was compared with that of mammalian picornaviruses. Like the 5′UTRs of mammalian picornaviruses, the 5′UTR of EoPV was rich in A/T, and had many AUG and small cistrons positioned upstream from the authentic initiation codon. The second structure of 5′UTR of EoPV was predicted with the mfold software. There were 4 stem loops, and conserved motifs of mammalian IRESs, including stemloop A, loop B (A/C rich) and polypyrimidine tract. Based on the characteristics of 5′UTR of EoPV, the genome was suggested to be translated with IRES mechanism.

Key words: Ectropis oblique picornavirus, mammalian picornaviruses, 5'untranslation region, structural analysis