COMPLETE NUCLEOTIDE-SEQUENCE OF A CYTOPATHIC HEPATITIS-A VIRUS-STRAINISOLATED IN ITALY

The molecular basis of the cytopathic effect induced in cell culture b y some hepatitis A virus (HAV) strains and variants has not been deter mined. In order to assess the molecular mechanism(s) underlying this p articular phenotype the genome of an Italian cytopathic isolate (strai n FG) was sequenced from cDNAs obtained by RT-PCR. Sequence analysis r evealed the presence of mutations common to either adapted or cytopath ic variants of HAV. In particular, amino acid deletions in proteins VP 1 and 3A were detected. Expression of protein 3A in E. coli showed tha t the N-terminal deletion renders this protein toxic to bacteria.