Identification of 5' capped structure and 3' terminal sequence of hepatitis E virus isolated from Morocco.
OBJECTIVE
To examine 5' and 3' terminal sequences of hepatitis E virus (HEV) isolated from Morocco, to confirm 5' methylated cap structure of the genome, and to investigate whether the 3' UTR can be used to distinguish HEV genotypes instead of HEV complete genome sequence.


METHODS
RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE) was employed to obtain the 5' and 3' terminal sequences of HEV Morocco strain. The 3' UTR sequence of the Morocco strain was compared with that of the other 29 HEV strains using the DNAStar software.


RESULTS
The 5' PCR product was obtained only from the RLM-RACE based on the capped RNA template. The 5' UTR of the Morocco strain had 26 nucleotides, and the 3' UTR had 65 nucleotides upstream to the polyA. The 5' UTR between HEV strains had only point mutations of nucleotides. The phylogenetic tree based on the sequences of 3' UTR was not the same as that based on the complete sequences.


CONCLUSIONS
The genome of HEV Morocco strain was methylated cap structure. The 3' terminal sequence can not be used for distinguishing HEV genotype for all HEV strains in place of the whole HEV genome sequence.
Chen
Guo-Bing
GB
Department of Microbiology and Immunology, Southeast University School of Medicine, Nanjing 210009, Jiangsu Province, China.
Meng
Ji-Hong
JH
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D001483:Base Sequence; D005814:Genes, Viral; D016679:Genome, Viral; D016752:Hepatitis E virus / Q000235:genetics*; D008969:Molecular Sequence Data; D009018:Morocco; D012315:RNA Caps; D015678:Viral Structural Proteins / Q000235:genetics
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D012315:RNA Caps; D015678:Viral Structural Proteins